Scalability: What is the best way to store and serve hundreds of GB of images for a heavy traffic website?
My answer to Scalability: What is the best way to store and serve hundreds of GB of images for a heavy traffic website? on Quora
If you’re not going to use a service like S3, your best bet is to run something like MogileFS (which was designed by LiveJournal for handling images) and stick Varnish (a screamingly fast HTTP caching server) in front of it.