RACE! PSP is a Neo Geo Pocket and Pocket Color Emulator for the PSP. The latest version is 2.16
RACE PSP 2.16 Changelog:
Time Rewind feature: map ‘Special: Rewind’ to any PSP button in the Controls menu to enable. See documentation for more information
Save state format has changed: RACE! PSP will still read the older save state [...]

Akop has today released RACE! PSP 2.16, RACE! PSP is a Neo Geo Pocket and Pocket Color Emulator for the PSP. New features include a time rewind feature, handy if you just hit the game over screen. You can now rewind a bit and try again.
RACE! PSP 2.16 Changelog:

Time Rewind feature: map ‘Special: Rewind’ to [...]

Great news we have another emulator to add to the collection for the PSP. RacePSP, the PSP’s Neo Geo Pocket and Neo Geo Pocket Color emulator hs been developed by Flavor. Although some bugs are present it looks very promising.

NJ has released another update for his Capcom Play System Emulators and Neo Geo emulator to version 2.3.1. Improvements to video and sound emulation and several bug fixes on his almost perfect PSP emulators. No support yet for full screen TV output, I hope that NJ can implement this soon as I would love [...]

Capcom Play System 1 & 2 Emulators and the Neo Geo Emulators were updated by NJ to version 2.2.2 today.
The update adds the ability to now use the “HOME” button to access the emulator menu during game play, as well as minor tweaks and various bug fixes.
Download: