If the firm you work at is anything like the one I do, you will move around to work with different teams depending on the project. Get things that are easily removable and can fit any of the cubicles you may sit in in the future. My cubicle has both tack boards and magnetic ones, both are covered in fabric, so I have big magnets to hold pictures as well as strong tacks that I can use to hold picture frames.

I bought myself this desk tidy: http://www.lazyboneuk.com/products/Pencil-Sharpener-Desk-Tidy.html and I can't help smiling every time I look at it but you did say you're on a budget. You can manke a desk tidy out of different hights of paper towel or toilet rolls stuck togehter in a cluster like this: http://www.impresssurrey.co.uk/Corporate-Gifts/Recycled/Paper/Recycled-Desk-Tidy-DESKTIDY.htm
I've had lot's of fun with stick on shelf paper. You can get it in lots of colours, it's easy to draw shapes on the back and cut them out. You could do a skyline to stick on the desk.

I'd say ditch the company issued calendar and get a nicely designed wall sized one. My calendar is big enough to cover a good chunk of cube wall and I use multi colored post it to save dates or make notes so it brings color to my cube, I love it!

get a few plants. They make it nice and nobody will look at you like youre a slacker for wasting time hanging things up. I've just got photos from travels, a few plants and a calendar I doodle on while I'm on the phone and people think my cube is cute (its actually quite boring compared to my home). Oh I've also got an oil painting from a garage sale hung up where a creepy eagle painting was. I got permission before swapping it.

Before you do anything, check with your colleagues to see what the office rules are regarding the cubicles. Even if the office doesn't require a uniform look, there may be safety rules about what you can put where.

I work for the government and I was able to find some really wonderful government issued industrial type office supplies around my office. Most of the folks who had them didn't appreciate how great they were so I was easily able to barter a set of new (boring) wire mesh letter trays for a set of heavy wooden and metal ones. I've got my eye on an amazing hat/coat rack in an office upstairs. So I'd say look around you and see what you like. Then see if you can borrow, barter, or buy.

Buy a Jade plant or other low-maintenance plants for an instant spruce.

3M (I think) might make a tape for fabric cubicle walls that has almost a 'velcro' backing. In my last cube, I had eight or ten printouts of vintage travel posters that I tacked up with the wall tape. Easily removable with no damage. Depending on the height of your cube wall, you can drape a 'hanging' planter with a wreath holder over the side. Have fun fixing it up :)

Big Lots, TJ Maxx, and Marshalls all carry inexpensive desk organizers and decorative items. Keep the accessories to a minimum, but add some color and comfort - I added a nice lamp, lumbar pillow (for my "guest chair"), desk organizers, and some framed wall art to my office for far less than $50.

Much like determining the proper attire for the office, take your cues from your coworkers - you don't want your cubicle to stand out for the wrong reasons.

A small, colorful lamp adds incredible warmth to a desk cube. Even if you have enough overhead lighting, it can often be harsh white light. A warm glow from a small desk lamp can make a big difference.

I second the plants, a colorful lamp, and stick on shelf paper. I had a boring metal bookshelf in my cubicle, which I covered in colorful green shelf paper. It made a huge difference. Also, it's easily removable. I would also recommend getting colorful storage boxes. Ikea sells those on the cheap, but you can also find them in Home Goods and Target.

A colorful, small rug in your cube can also make your work area seem so much more inviting and home-y. And I agree with tbgboodler about lamps. Lighting makes all the difference.

Check out how much other employees decorate their cubes. You don't want to veer too terribly far from corporate culture at first. So if the majority of people have a few snapshots and a calendar and a plant, don't go overboard with fancy desk accessories and artwork and stuff right away.

You can usually get away with a plant or two, a nice calendar and one piece of not-too-big artwork. Then concentrate on finding office gadgets that suit your style--a letter opener, a tape dispenser, stapler, scissors, and the like. You could probably get a desk blotter or calendar to brighten up the desk top. And definitely a lamp.

What you have inside your drawers, on the other hand, can be as wacky as you want, because others won't see what you have in there. So colorful file folders, cheerful drawer organizers/dividers and the like--whatever you want. You could line the drawers with wrapping paper, so every time you open a drawer, you get a burst of color.

Once you've been there a while, and established yourself as a competent, reliable employee, you can start to decorate a bit more.

I was in the same boat as you about a year ago when my company moved into the new building we're in now. I spiffed up my cube with some line art and a Jane Austen quote, some little pictures I've been carrying around with me, a few mason jars for snacky-food storage, and bright colored accents. I wrote a blog post about it, though, it's been a year. It might be time for an update!
I've since taken down the red Christmas lights, added some puffy white coffee filter flowers and a few more mason jars, and a wall calendar of my favorite architect (Frank Lloyd Wright).
The trick for me is having things around me that I like looking at for 8 hours a day.
Best of luck!

candy jars :)

Two favorite online sites for office stuff:

http://www.seejanework.com/

http://www.russellandhazel.com/

(I'm kind of an office supply junkie)

For an elegant look, add real lamp and bring in some supply organizers that AREN'T from a big-box store -- use vintage ashtrays, little chinoiserie bowls, etc. Add a nice throw or sweater over the back of your chair, and you're good.

I disagree with the other commenters about plants -- they look a bit secretary.

Pick pieces that make you smile or "speak" to you. You will spend more time with them than sometimes the items in your own home.

My favorite go-to place is Home Goods. Their stock changes all the time so if you see something that "speaks" to you, buy it!!!!

I got an oversized blue ceramic queen chess piece. My IT co-workers geek out of the symbolism of the queen (she can do anything she wants ton the chess board). I also got a fabulous bronze ceramic elephant that I just adored. My Indian co-workers commented on the excellent symbolism. Ganesha is the Hindu god who removes obstacles, perfect for sometimes frustrating work situations.

OMG Lisa (montreal)!! non-secretaries need oxygen too!...plants help us have healthier air in our offices filled with so many toxic fumes from the cubicles themselves/rugs/computers/faxes/and sometimes the MAN boss's cigar! ; ) I am so getting a lot of plants and also some of your cool suggestions asap..!

Paperweights have an under-recognized advantage. I keep very tidy and organized stacks on my desk. Topping them with a paperweight keeps my coworkers from just throwing paper wherever on my desk, and also looks pretty and tidy.

I also love having a small table lamp. As @tbgboodler said, it warms up the space and gives me a break from the harsh flourescents!

Just don't go overboard. A few personal peices are enough! I keep two framed pics, two paperweights, and an analog clock on my desk. You still want to look organized (i.e. not cluttered) and professional. Coworkers should know your mind is on your work, not wandering through personal artifacts and nostaligia on your desk (although, I am ATing when I should be working, haha)!

Hit up your local dollar store for funky folders and paper pads. I bought a bunch of really bright fake flowers and put them in a cheap vase to add some color. Dollar store will also have cheap picture frames for your desk, some desk organizational items, and brightly colored pins, elastics and paper clips. I funked up my cube for less than 25 bucks!

This depends entirely on the look you're going for, but for nerdy touches I love thinkgeek.com. It has cute swag like ninja star push pins, floppy disc post-its, and the classic red Swingline stapler from Office Space. Definite conversation starters!