I started online gaming on my PS2 late last year, well, just playing Burnout 3 if I'm honest.
When I first signed up, Sony promised to send me an updated Network Access disc that included a full game called "Hardware: Online Arena". Well, I thought, it's free, so it's probably not up to much, and you don't actually NEED the Network Access Disc once you're set up, so I never bothered chasing it.
Anyway, something reminded me about it last week, so I rang them, and they sent it me...
And it's really quite good! (for free)

Up to 16 players careering round a map in a selection of jeeps and tanks, with all sorts of power-ups, trying the blow the heck out of each other... in my new philosophy of quick 'pick up and play games' it fits right in! I've decided I now really need a headset too...
There aren't that many maps, and only about 8 vehicles, so I can imagine it might get boring fairly quickly.
But then again, I have yet to take Timesplitters 3 online... Mwah hah hah (oh, I'm dead).