If your shower is on the small side there's a good change you have one of those hanging baskets that nestles down around your shower head. That's all well and good if those things would stay put and work with a variety of different shower heads. Forget traditional mounting, why not relocate it somewhere easier with the use of cabinet pulls?
We ran across this fun idea over at The Family Handyman and although it might require a bit more effort on your part to hang things up, it looks like it could be worth it.
The ability to place something of this nature in a location where you don't bash your wrists on it as you wash conditioner out of your hair is a serious bonus. In addition, if you have tiny tots in your house, being able to mount one low where they can reach it just outside the shower curtain would be super great. You can check out the how to mount them from the photo above or find more information at The Family Handyman.
Image: The Family Handyman

Shaw's Original Fir...
I would do this except I haven't had a plastic shower caddy since (?) never. But it does make me think about other uses for drawer pulls and it is a good idea.
Well, doh! What a good, simple idea.
I would suggest running a little waterproof silicone calk around the edge of the knob where it meets the wall. You want to keep absolutely all moisture out of the hole you're making.
Great idea! Saving this for later.
For you apartment dwellers those Command hooks work really great. I use one on my tile and it has been up for over a year w/o any problems!
one of my goals in life (or at least real estate) is to finally have a bathroom that doesn't require a caddy in the shower. until then....
@kassgood, those aren't plastic. Caddies are usually either metal or coated metal (as in the above pic). I have yet to see ones like that that are plastic.
@jsev not to brag, but you'd love my apartment, 3 shelves on both head/foot ends of the tub with enough room under the bottom shelves (and a wide enough ledge) to put another bottle, or as in my case, hang a razor on a little suction cup.
I did just that in our house - I located the knob for hanging at the opposite end of the enclosure from the shower so my soap doesn't get wet and melt and the water doesn't sit by bottles and make icky gunk.
Duh, what a great idea! It's a perfect solution, especially in group houses when several housemates have to share a bathroom.
Another solution to the problem - I put up an extra shower curtain tension rod along the tiled inside wall of our tub. I hung a few spare shower curtain hooks over it, and they worked well for suspending loofahs, backscrubbers, etc. It's a particularly nice solution for washcloths - before, I would hang my washcloth over the shower curtain to dry, and then it would fall to the floor when one of my roommates moved the curtain to take a shower. Now, we have space for each of us to hang our washcloths up.
This is a cool idea, but jess13 is right: this NEEDS waterproofing. I had a bathroom with an ENORMOUS (> 2'x3') medicine cabinet style mirror, which was a glass sheet mirror mounted on a plank of wood, painted with high-gloss latex paint, with a hinge running down the whole of one side with about a dozen screws holding the plank to the hinge. I am sure this was VERY secure when it was installed, and for years afterward. If I had done this, I would have congratulated myself on doing a good job making a solid, beautiful cabinet door.
But fast forward to when I had the apartment, probably a couple decades or more after someone installed it, and one day while I am showering, it slips right off it's hinge and totally shatters the (beautiful, vintage) porcelain sink. The wood plank had become too soft with years of moisture seeping in through cracks in the paint around the screws, causing them to slowly slip out. Even if it seems good right now, with bathrooms you always need to be aware of the power water and time have on materials. It may be great and secure now and even stay that way for a few years, but you run a very high chance of that eventually rotting out and leaving a big hole in the shower wall. If it were a necessity, I'd say go for it, but from my perspective, you're better off just getting a different kind of storage rack, or change how you shower so that you don't have to keep all of your stuff in the shower all of the time.
I live in a house with three other grown-ups, a two year old, and a bunch of shampoo and conditioner bottles for all of our different hair types precariously perched on the towel bar.
I'll be bringing this up at the next town hall meeting - it's a great idea, I actually have a couple of knobs we might could use, and we'd be able to keep the tub toys in the tub rather than next to the toilet (yuck!).