The headline should explain it all. The team at ****z has discovered an exploit that can now be run on all of Sony's official firmware including the latest, 3.03. You will need an unpatched version of GTA: Liberty City Stories to take advantage of the exploit. Right now, there's a proof-of-concept available at ****z's website, but it will be a matter of days until all PSP owners, including 3.03 users will have a downgrader ... as long as they can secure a non-patched version of GTA (note: copies being sold in stores right now most likely are patched!).

More... (http://www.news4gamers.com/psp/News-20996.aspx)