For all you geeks trying to get Google Videos on your PSP, here is the elusive information that I couldn’t find online anywhere. (The Google links on this page, were utterly unhelpful)

Easiest way is to download the psp version of the video to your desktop, then plug in your PSP and migrate to the MP_ROOT folder. You need to put the videos in a folder called 100ANV01 and rename them using this structure: MAQ#####.MP4 (where # is a number)

I had put videos on my psp before, but they went into a folder called 100MNV01 and had a different file naming scheme. There you go. Cheers.