I've got two different challenges for you guys.
The first is similar to the Dual Wield Peel above, but just use the banana's whole. This makes them blunt (mace, hammer) type weapons instead of whips. I tried this after I discovered that it was taking forever to kill zombies with my banana peels. I seriously knocked one guys head off nine times. He just kept reattaching it. I finally had to kick him to death.
The second one I call the Lightbringer challenge. Do as above (leave kenny behind), but instead of getting a banana, go straight into the dungeon. In the first room, there should be between 1 and 4 lanterns. Take them, and equip two (one in each hand). They count as their own type of weapon (uncategorized, I think) attack pretty fast, and do suprisingly good damage. I got to Attnam for the very first time trying out this challenge. Died on GC2, somewhere I had
never been before.
For the second challenge I recommend having six lamps in your inventory (2 wielded, 4 stored) at all times. They will eventually break, but not until around UT3, in my three trial runs. Another nice thing about this challenge is that these things are ridiculously plentiful. Don't bother trying to get them repaired (not even sure if you can, actually), just drop 'em pull out some new ones.
Have fun!
EDIT: Quick question! I tired in one game to harden my lanterns. It told me my INT was too low. Can you really harden them, and, if so, in what and at what INT? (Dual Mithril Lanterns FTW!)
EDIT:AGAIN: I've only tried this on vanilla Ivan 0.50. So yeah.