It would be nice if there would be a possibility for paying in Euros! (or don't the British don't like our money?
Why don't you offer the possibility of mailing selected games?
And I think the pgn-standart (4.3: Line lengths) is something like 79 characters.
A tricky thing for those who like coding
would be on-the-fly-ziping and mailing this file!
In the message-log I can't see who played which color. (Why don't you show a minimum of information on every page according the actual game?)
I like the site really a lot and all the existing features are great and enough - but I think one could make it a little bit better...