I got my 3rd one about a month ago from Sony and it was the GT3 demo, It seems that they are using my old PSX registration of the old days to send out the demo's.
Over the years I've been getting 4 demo discs per year, just because I filled in the little slip of paper all those years ago when the PSX first came out and when I got my PS2 last November I did the same again, the first demo came about April.
If you go to the main Sony PSX site and have a good look around you will find a registration form to fill in online. It's in the PS2 section. Also the people who bought GT3 have another web address to get another free demo.
Did anyone who pre-ordered there PS2 keep getting money back coupons from Sony? I keep getting £10 cash back, all you have to do is if the game you bought is in the list, then send your game receipt to them with the coupon and you get some money back. So far I've received £40 in total off Sony and waiting for another £10 off the GT3 game. So I does pay to fill in those little bits of paper :) * *