[Stallion]

PS3 Hacks - Hacks, Cracks, Mods, Homebrew, Utilities. » PS3 Filer v0.0.3 with NES Emulation Hack Sony Play Station Portable

* Unzip the ps3filer.zip archive
* Copy NES ROMs to the AVCHD directory
* Copy the AVCHD directory to the root of a USB/Flash drive
* Go to the device in the XMB video menu and launch “AVCHD”


http://www.ps3-hacks.com/download.php?id=57

There is also a video of it on youtube:

YouTube - NES GAMES ON PS3!!!! (From XMB!)

I can confirm that this works but still use at your own risk