Nope, not going to work. ANY sort of network adapter will need to install drivers to work.
And besides, that's a "client adapter". You'll have to config it to act as a hotspot (i.e. "ad hoc network"), which takes even MORE config tricks, to connect to your iPod Touch. Sorry, not going to work.
If the school blocks sites, how is you connect iPod Touch up to it going to bypass any of that? There's a leap in logic here I'm not following.
EDIT: Actually, no, it's a leap of logic on your part. A: School uses Internet Explorer + B: School blocks traffic does NOT = C: I can bypass it with different browser.
The block can be put in at the router level. Indeed, the block usually IS at the router level, so there's nothing for you to bypass locally.
Obviously, the only way for you to find out is to test it, and here's a much easier way to test: why don't you get a USB flash drive, 1 or 2 GB is enough, and load a "portable" version of Firefox or Safari on it? Those are "no install" so as long as you can launch it you're go... and if you can get out we'll see who's right about the block. :)
Why use a complicated bypass solution when a simple one will do?