The good folks at IGN have compiled a fantastic list of games that support ad-hoc (local) wireless and infrastructure wireless. It's been slow to start, but more and more games have been adding support for internet play and downloadable levels, and they should be commended. The games that use Infrastructure mode include:
- Ratchet & Clank: Size Matters
- Monster Hunter Portable 2 (downloadable levels only)
- Metal Gear Solid: Portable Ops
- Kingdom of Paradise 2 (downloadable items only)
- Tales of the World: Radiant Mythology (online leaderboard & downloadable levels only)
- Mahjong Fight Club
- P-Kara
[Update 1: This list is only of games present at TGS. There are tons of other games that feature wireless support that aren't on display.]
