While you plan trips on Dopplr and it’s all bound to, “I am in City X from date to date”, Plazes is more about the activity – for example, “I am doing X @ plaze Y”. On top of that, plazes also allows you to schedule all your events, meetings whatever and use it as a calendar app.

Plazes in general is far more detailed on activities and what is going on around you. Like, when people use the mobile app (or text message) you can actually find out where they are and what they are doing, which is what 80+% of all phone conversations is about anyway.

What I find particulary interesting is, is that you also get a history of your travels – and not just on the city level (e.g. from 08/03/05 until 08/03/10, I was in Berlin), but also as in, “yesterday I went to Prospect Park in Brooklyn, then I went to a bar 4 blocks from there and back home to Manhattan, today I went down to the Seaport in the Financial District”.

Now I have no grudge against Dopplr (I use it also since I am a geo-location junkie), it just got different features. Like you put in a trip, select train, airplane or car, calculate your carbon totals and just see where contacts are at. You don’t see if Allen hangs out at a bar in Brooklyn tonight, you just see that he is in New York.

Now plazes and Dopplr are both useful to me, and I wish they would integrate with one another, and I wish more people would use it because that component is what makes it really valuable and creates -the- use case.

On top of that both could go in bed with Yelp and/or Qype to make me even happier.