I've also done fruit roll-ups, or fruit leather; there's lots of recipes online. I just used a mixture of applesauce and grape juice, spread layers of saran wrap on the racks, poured it in (carefully!!) and about 6 hours later, homemade fruit roll-ups! Sans all the nasty preservatives and such.
We've done A LOT of beef jerky. London broil works the best, as it tends to be on the leaner side. Sirloin does pretty good, as well.
I've even made chicken jerky, and it turned out pretty tasty, even if it sounds a little gross.
I still haven't tried any ground meat as jerky, but I've been meaning to. They make a little jerky gun for squeezing out the meat, but I don't have one yet.
There's all kinds of great marinade recipes online, just make sure you marinade at least 24 hours!
Oh, and the banana chips didn't turn out at all, much to my disappointment.