As of right now i don't know of nebody that has networked with a ps2 and pc. I know of xbox and pc though. but they are alot alike.
Links for ps2 memory car readers/flash memory cards.
http://ps2modchip.com/search.php?page=psx40
http://www.ps2modchip.com/search.php?page=ps26
To the MODS i know these sites may also sell mod chips. I do condone or endorse buying/using modchips for ne reason.
Also the Codebreaker for ps2 has a new DAY 1 tm thing that lets you d/l save games/codes on the realease date of the game.