Dave Zatz has updated his handy TiVo To Go guide to include instructions for moving your recorded TiVo content over to Sony's handheld gaming device. It's a little patchy, with a few steps of manual transcoding and the like in between, but I'm sure someone will build a nice all-in-one tool soon enough. Until then, Dave's got the basic steps (and plenty more info for transferring your TiVo To Go content elsewhere, not just the PSP).
TiVo To Go Unleashed! [ZatzNotFunny]