I'm spending the morning registering for conferences. STOC early deadline is April 30, ISIT is May 1, and EC is May 6. I'm sure there are others coming up. Remember to sign up now! (Why pay the "late signup" fee of $100 or so?) And please say hello if I see you at any of these events.
In terms of pricing, early rates are $400 for EC, $500 for STOC, and $675 for ISIT. I'll let people argue the relative value one obtains for one's money at the different conferences. It's worth noting the STOC fee includes the Tutorial Day on Saturday; tutorials for EC and ISIT are extra.