On not being in two places at the same time

I have a membership at Constitution (this year's Unicon, held at Murray Edwards College in Cambridge on 31 July - 2 August; Sean Punch, Steph Swainston, Harry Gee and Sib Machat as guests of honour), and a membership at Satellite 2 (a convention to celebrate the 40th anniversary of the first moon landing, to be held in Glasgow on 25 - 26 July; Iain Banks is guest of honour).

However, in both cases I will be in Canada at the time.

So, the memberships are for sale. The Constitution one has gone, but the Satellite 2 one is still available for 40 pounds.