Bholland and I have made two small changes to iBoy 0.7.5 and released it as version 0.7.5.1.

Download it here:
http://ipodlinux.org/Image:Iboy0751.zip

The two changes are:

1) Support for iPod Mini 2G. Sound works!

2) Support for diagonal directions controlled via iboy.cfg
--> For example if you want a touchpad button to mimic pressing -both- up and right at the same time, you can set it up like so:
kb_t1=PAD_RIGHT_UP
This is useful for games like Link´s Awakening.

Please check the wiki for up-to-date information regarding iBoy, particularly installation info. The wiki should be a good, clear source of information.
http://ipodlinux.org/Iboy

If you have success installing iBoy, please post on this forum and then the wiki can be updated. It would be good to know which iPods this version works on.

Testing results:
Mini 1G: unconfirmed
Mini 2G: works
3G: unconfirmed
4G (Grayscale): unconfirmed
4G (Color): unconfirmed
5G/5.5G: works. colors incorrect for Gameboy Color ROMs.
Nano 1G: works. Scaling option does not work.