If $500 is acceptable for you, I just ordered a Canon Rebel XS from Adorama for $500, with a 18-55mm IS lens and a 70-300mm lens ($150 instant rebate with the extra lens, but the camera + 18-55 IS lens is still about $500). With memory card, extra battery, filter, and a bag (plus shipping), it was about $650 for me.

Otherwise, you can probably find better used deals