I use a PS2 with FreeMCBoot installed via the independence exploit (YAY FAT PS2), used uLaunchElf to extract saves, use a program on my computer to convert it to .mcr (don't remember the name of the app, sorry), then used CWCheat on my PSP to make it into a PS3-compatible memory card file, and then moved the saves over to my PS3.
I would also like to note that if you have a slim PS2, and you get Swap Magic, you'll need a different disc cover. It's stupidly easy to install, it's just a pain to get. If you're enterprising, however, you can block the 5 sensors inside yourself (look up how, I never bothered to do it, the new cover is much less of a pain in the ass to install)