I'm as fed up with the server slowness as you, trust me. Although, we did discover what was slowing things down - at least what was contributing towards it.
Our server log file, for whatever reason, was weighing in at a massive 2 GB - We think, due to a bug in our server software, which we have requested our hosts patch to the latest version. Anyway, the result of this was when you visited TweakTown it would take ages for the log file to be accessed and written to - hence the time it took for pages to load. We have since deleted the log file and disabled the feature in the effort to keep things as fast as possible. Even after our server upgrade a couple of days ago, we are still having issues. We have decided if the traffic continues, we will order another server which will be for the database, and maybe an extra server dedicated to the forums.
I'll keep you posted on things as they happen!