As a foursquare user, I totally agree with all of these points. The personal journal point is especially cool. I didn't realize it until I tried looking at my past checkins, but it was actually really interesting to look back at what I was doing last summer, what I did when I went downtown with some friends last winter, where we went on vacations, etc.

This update looks awesome, nice work! I especially like the new Friends tab - much more useful now that it's actually possible to view multiple prior checkins rather than just the most recent.