Based on this, yo shold be able to redownlod the version compatible wioth your iPod
Note this only works if your previously purchased the app.
Although, where do you see that it says it only works for previously purchased apps, or is that from experience? Like, if I made a new account, would I not be able to download Remote from my iTouch?
Also, what about telling iTunes itself to NOT download updates for stuff that isn't compatible with my devices? Still not a way to do that yet?