Thease apps might be too large, unless you choose to put them on a flash card and then you would probably need to copy them to all the cards you are using to insure that they are allways there. You might want to search for PDA sized applications. I found a possible candidate by doing a search for "tiny linux apps"
I'm working with QT and Opie on Zaurus and on custom hardware, there are any QT, QTOPIA port to 770?
As far as I know, there are no QT ports to Maemo. It'd be an interesting challenge, and there's no reason you couldn't remove the entirety of the Hildon Application Framework and replace it with Opie.
However, no-one's done it yet, despite all the claims that QT(opia) is *so* much better for mobile devices than Gtk+. Personally, I'll believe it when I see proof.