Snipershoots, A330/500D and D3000 do not have specific advantages over the other. Why not consider Olympus and Pentax as well?
Hahaha, this is coming from a Canon/Alpha user.... Please both camps of users don't flame me....
If cost is an issue now, suggest you try getting a camera from
http://www.clubsnap.com/forums/forumdisplay.php?f=64
I'm sure there are friendly bros out there who wouldn't mind you testing their cams and sharing info with you. Just be considerate and suit their timing and buy them a coffee while at it.