New map features in our Android guides

We've just uploaded three new guides (Warsaw, Vienna and Belfast) and updated our Amsterdam guide.

The main new feature is that our maps now use tiles, load faster and are easier to navigate. The tiles we use are based on the Open Street Map, and we use Cloudmade to skin the map so it looks good.

If these four guides don't produce any unexpected crashes, and get good feedback from users, we will update all guides the coming days.