Thanks Jason that's going to be very useful.
I actually "run" a VPS (not that I know what I'm doing mind you). The guys I rent it off of are very helpful and usually do things for me, but I am trying to learn as I go.
It gives me a bit more control over what I can achieve for my clients. Asking some hosts to increase max_file_size from 2M is like asking for the moon to stop :-)