Robert A. has done a good straight port of Penguin Scramble that uses the TIFF exploit. The game is easy to learn: you take your penguin and you scramble it through an obstacle course of icebergs and glaciers. Here's what Robert A. had in the readme:

* Originally coded by Percival (Moderator @ PSP3D.com)
* Ported to 2.7-2.8 TIFF by Robert A. (Admin @ PSP3D.com)
* To install, simply place the 'PENGUIN' folder included in the 'PHOTO' section on your memory card (works on 2.0 - 2.8 firmwares).
* To run, open the 'PENGUIN' folder on your PSP, and the game will autostart.
* *Changelog* v0.2 - 9/16/06: First release.
* Thanks to the Noobz team for the TIFF exploit and SDK!

And for those of you who are having problems, Cody L. from PSP3D had this advice:

* If you're having trouble getting this to work, try highlighting the 'PENGUIN' folder in the 'PHOTO' menu on your memory stick, then press 'Start' to start a slideshow.
* This seems to be the most reliable method for running homebrew using the TIFF exploit.