Where2.0 registration early-bird pricing ends today (with an extra
10% off via whr09twt1 code now with 25% off goodness with whr09cm25 - or even higher discounts if you qualify under one of the other groups (students, academic, government)).
For me - the most compelling thing about Where2.0 this year is seeing the round-trip evolution of GeoHackers 3 years ago, to viable, growing businesses. It's been widely recognized that the Where2.0 follow-on, WhereCamp, is where innovators and thinkers spend the weekend considering what the future of location technology is - but now it's even becoming mainstream.
Steve Coast went from a crazy idea, to a global community, to a funded-global business and is talking about Ubiquitous GeoContext. Dennis Crowley has done it before and doing it again and discussing the social-locative ghosts of past and future. DC is being represented by Eric Gunderson, Tim "Chippy" Waters' open-source map rectifier is being used in major libraries - and Chris Spurgeon, well, his talks are awesome and the perfect way to end the conference with Maps in Space. And there are even more that I believe will be announced soon.
And there may even be some cool locative games to join in on.
(disclosure: I am a member of the Where2.0 conference selection committee and as such obviously think everyone speaking is awesome and should be heard by as many people as possible.)