OK, I've seen that one post where people talked about this and provided some links. I wanted to add my own, though I'm doing my best to wait for several months to get a PSP (pay off other debt first, my usual wait and see approach to expensive, first generation hardware).
But I've been gobbling up PSP information like crazy in the meantime. I've found the following shareware utilities that (claim to) sync the device with your Mac's iTunes and iPhoto libraries. I believe that all of them also have a movie compression component that allows you to convert and transfer various codecs over:
PSPWare -
http://www.nullriver.com/index/products/pspware
This seems the most promising (and maybe the newest?) thus far, though I have no real reason to claim it so.
iPSP -
http://www.kaisakura.com/iPSP/
Users have been reporting back on this as somewhat problematic (crashes, doesn't transfer video files well)
PSP Video 9 -
http://www.pspvideo9.com/
For those with a PC or VirtualPC. This seems kinda exciting because they talk about "PSPcasting" and RSS.
Mobile Media Maker -
http://www.makayama.com/mobilemediamakerpsp.html
Also for the PC.
Tutorial on using ffmpegx -
http://homepage.mac.com/major4/psp.html
I believe iPSP uses ffmpegx. And I think this is a free, open source thingie.
The ones that I envision myself using, for the moment at least, are either PSPWare or iPSP. Both for their integration with the iApps and a relative Mac-like interface without lots of intermediate steps in between tasks.
If anybody has experience with these, either now or in the next few weeks/months, please post here to relay your impressions. And if anybody else finds other utilities, please add them here. We'll see how long I can hold out.
Also, just found this site, PSP-vault.com, that allows people to upload and share game save data (neat!) and links to PSP utilities (most like all of the above are included). A good starting off point for all things PSP looks like.