I don't know if this is the absolute cheapest solution, but I know the guy who runs
www.schostpro.com
and I have been a satisfied customer for the past two years. In terms of uptime and support (even when your question is stupid) I've been impressed.
I guess if I were in your situation (hosting pictures) I'd get a basic account with an extra GB of storage (1350 megs total) for $7 a month (8GB monthly bandwidth) or an advanced account (750 megs storage, 18GB bw, $10/month)