Have you thought about visiting a craft store near a university, or even the school's bookstore? I recall seeing Greek DIY letters so sororities and fraternities could make their own decor when I was in school.

I would also suggest possibly attaching magnets or something along those lines and attach it to a board you can hang from the wall. That way you can write another poem down the road if you want to change it up a bit.

Some quick Google searching found lots of options for you. First you need to decide if you want wood, vinyl wall decal, magnetic, etc. Here are some ideas that I was able to find:
http://www.woodlandmanufacturing.com/other-signs/greek-letters
http://www.cafepress.com/+greek-alphabet+magnets
http://www.mybelvedere.com/vinylletters/greekwallletters.html

Painting your quote on the wall sounds like your best bet. If you can't paint your walls, paint something you can hang on a wall, like a framed piece of poster board or plywood and hang it. If you are hoping to fill a large space, get several boards or empty frames and do one word for each. Hanging individual letters of a word can be mind wrecking once you get past 12.

Not sure about where to find the letters...ebay, etsy? But 3M hangers are great for lightweight stuff.

Have you considered painting the letters on small canvases or framing them (in small frames like Ikea's clips) and hanging them in a grid? It would eat up wall space and provide an opportunity to add color for added interest.

I actually just did a similar project in my apartment (and wrote a blog about it, of course: Cheap, DIY, and nerdy). I picked up my letters at Hobby Lobby and painted them with craft paint. One way to get your Greek letters might be to stencil them on cardboard, cut them out, and paint them. Hanging them was pretty easy, I just picked up some permanent mounting squares that have held up really great so far.

Good luck!

I'm sure you have a local sign-maker, who can make vinyl cutouts in any typeface and alphabet.

It's a nice idea! I'm signwriters and for sure if you contact a signage company in your area, they can help you. I really like the design with wood.

I was just envisioning a poem strung letter by letter on a ribbon, like pennants. Just a passing thought...

I can laser cut them using my 30 watt laser if of would like. Depending on the number of letters, I would charge from $50 to $150. Send me a message and we can talk specifics.

Thanks so much everyone, very nice ideas!!
SHERRYBINNH and ITSALLABOUTTHEG posts gave me the following idea.

I will print them in photographic paper and hang them in a string or ribbon with pegs. Not sure how this would turn out, especially because there won't be much volume. If it doesn't work, I'll cut the photos as stencils and spray paint on canvas or something. Looking at the signmaker options seems to exceed my budget quite a bit :(

I will send a picture of the result.
Many many thanks!

Find a local sign maker and the whole quote made for you in vinyl. They can work from a computer file, so you get exactly what you want. Then, you only need to apply it to the wall.

Maybe it's obvious, but I meant they can work from Your Own computer file.

I just remembered this place - Words Anywhere. You don't even have to leave your computer to order.

http://wordsanywhere.com/?gclid=COLDpZ-Ch68CFUhN4Aod5AGBhg

We did the alphabet around my daughter's room in 26 differnt fonts.... I found a local shop with a CNC machine and provided them with an adobe illustrator file of the different letters, arranged on 4 foot by 8 foot template. They cut them for me out of MDF. They came out amazing - I spray painted them, and then hung them all using the 3M poster strips (They also sit on a piece of trim).

(Yes, we stole this idea from Sarah Richardson...)