Dark_Alex in conjunction with Mathieulh has released the first known 2.71 downgrader. The 2.71 downgrader is a port of the old 2.50/2.60 downgrader to use the recently discover libtiff exploit. The procedure is almost identical to that of the 2.50/2.60 downgrader except this time around you won’t need GTA. As always, be very cautious. Homebrew applications like this that write the PSP’s flash memory and can potentially turn your PSP into an expensive paper weight. If you do decide to go through with it, be sure to read PSP Updates’ spiel about it; you’ll also find the download links there.
Update: Dark_Alex and Mathieulh have released a bug fix for the 2.71 downgrader to fix premature bricking if the flash process failed.[via PSP Updates]