Well, overall our first day with whereyougonnabe went well. A couple of hundred people from 20 countries have signed up so far, we've had a good amount of positive feedback, and the system seems to have been running well. Personally I have already discovered quite a few interesting interactions with friends I didn't know about before, which bodes well for the system being useful. We got some coverage in the blogosphere from James, Glenn (who will be close to me next week) and Jonathan (who had some constructive feedback and liked the Google Earth integration). As Jonathan commented, the effectiveness of it is very much dependent on the "network effect" - the more friends you have using it, the more useful it is. This is one of the key reasons we built it on top of Facebook (initially) rather than doing yet another independent networking system. I personally am pretty reluctant to invite friends to a new online networking system until I'm really convinced it's valuable - but of course it's not really valuable to you until you have a lot of friends on there, which is a big barrier to success for a new system.
We had a few issues with browser compatibility which we hadn't uncovered in our alpha testing, but which got quickly exposed with a larger group of users. We currently don't support Safari but we're working on that (we knew about this before but it turned out that our nice error trapping worked in the main application but not on the initial sign up page, so apologies to the Safari users who experienced ungraceful crashes trying to sign up - this will be fixed tonight). We've also discovered some issues with IE6 which we hadn't come across before, and we're debating whether to try to support that or whether to follow the "Save the Developers" campaign!
We now have a whereyougonnabe forum up, so please use that to let us know about any problems or to post suggestions for future enhancements. Thanks to everyone for all their interest and words of encouragement!