Looking to get a new camera?

I'm looking to buy a camera as someone who is just starting to get into photography! I currently have a pretty basic point and shoot (panasonic dmc-fx12) and i'm usually able to get pretty good pictures from it

and there's nothing that a little bit of photoshop can't fix.

however, i'm looking to upgrade and would like something a bit nicer - i've gotten nikon d90s and several canons recommended to me but would appreciate any input you guys have to offer!

also do cameras tend to run cheaper if you buy them used/where is the cheapest place to buy them?
i have a budget of about $500

KODAK

I have a Canon XS- it's my first DSLR. I love it. It's pretty user friendly and I adapted to it quick- I now feel funny when I take pictures without a view-finder! It's a great little gadget and it's taken some really nice pictures for me. It's about $500 and it's just great. I've heard positive things from Nikon's too, but all of the pro photographers I've talked to recommend Canon!