PSGroove
This is the PSGroove, an open-source reimplementation of the psjailbreak exploit for AT90USB and related microcontrollers.

It should work on:

AT90USB162
AT90USB646
AT90USB647
AT90USB1286
AT90USB1287
ATMEGA32U4
... and maybe more.

This software is not intended to enable piracy, and such features have been disabled. This software is intended to allow the execution of unsigned third-party apps and games on the PS3.

Also:
"This software is not intended to enable piracy, and such features have been disabled."
And
Hints that it is coming to iPhone and PSP:
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