Best deal I came across was the Kingston RAM at Officemax. I get coupons in the mail for them all the time, so their $80 - $20 MIR = $60 deal for a 512MB RAM turns into a $45 deal.
So, keep an eye out for Officemax coupons in the mail, and their weekly sale ad will almost always have a $60 512MB RAM deal in it.