The Google Developers map for finding the Google I/O event near you really sucks.
1. If you open the direct link to finding an event your browser jumps down to the find interface, but at the top of the page a modal dialog opens, asking you to sign in. Since it's out of the viewscreen, though, you can't cancel it and you can't react with any of the elements beneath it, so you're out of luck.
2. Reload the page without jumping to the find interface and log on, or cancel the login dialog, and you can then scroll down to where you were before. When you get there you can search for an event. The autocompletion works fine, but you have no feedback when you press enter or click the magnifying glass. I thought some asynchronous stuff was going on in the background, but it seems that the app searches very quickly - it only does so though, once you click out of the search area.
3. The map where you see the world orthographically, but only the top 10% of the disk? Totally useless. No labels, no way of scrolling without clicking on other events...
4. I entered "Frankfurt" in the search field and although there's an event in Frankfurt, it told me that Darmstadt was closer. ...Not really.
There! Those are all my complaints. I'm still looking forward to the keynote!