If I were a VC this is a startup I would back.
If the money in a gold rush is made from selling picks and shovels, then Openfount are selling stainless steel Web 2.0 tools for the price of plastic ones.
They have built value-added products upon Amazon’s excellent S3 storage and EC2 pay as you go grid computing.
The most interesting is the distributed file system product. They give you a disk image to load onto S3. From that you can instantiate as many clustered machines as you want and have them share the same disk, with infinite capacity.
Simple and elegant. Stuff that used to cost six figures for a grand or so.