Maddeningly the very day before the server everything was hosted on completely crashed; I had to completely migrate the code to a new server (which for €6 less per month gets me 32Gb of RAM, 3Tb of space and an i7 3770k - from Hetzner). I ordered the new box at 15:11 and by 15:21 it was online and available. That evening I managed to get everything up and running. Migrating the data from the systme that crashed took a while longer as the RAID array was pretty gone - I could get a few Gb at a time before I'd get a stream of
Input/Output errors. Thankfully though everything was copied over and the site handled a whole bunch of concurrent users without any hassle.
We had well over 1,000 uploads in just one day - up til then we've been getting maybe a few hundred per week; even better we had some lovely feedback and it seemed like people were geniunely having fun with it which has been a big part of the reason for it.