Well...all done. I was right though - they had a HUGE queue which for ages didn't move. Silly SU. Did mean I got to decline lots of leaflets and chat to battle re-enactment folk.
But I got in eventually and signed up with the 4 socs I wanted: IFIS, GameSoc, RockSoc and Battle Re-enactment. RockSoc looks like it's really eager this year, although they've got Arseface as treasurer, so I expect he'll be off to sunny climes soon.