It looks as though the site has been down for the last 6 or so hours, I can only put this down to the new influx due to the OXM article that I believe hit the stores today.
I've spent the last couple of weeks trying to optimize the site to handle a lot more users - most things are now cached and I've reduced the number of hits on the database for each page considerably. There's more that can be done, but it may be that I simply have to buy a new server.
Anyway, we'll see how we get on for the rest of today....
Thanks all, and my apologies for any disruption.