Pitch: A site that lets you create your own travel blog or food blog based on geolocation check-ins.
The site connects to your Foursquare, Gowalla or Facebook Places check-ins and allows you to select one to write a blog post about.
Travel bloggers can write about the places they've visited, food bloggers can write about restaurants. There's probably other uses.
The site using Foursquare's API could then post a link to the blogpost in the "Tips" for the location, allowing other users to access the post from the app or site.
Would this work as a platform itself, or would it just make a good WP plug-in?
Just an idea.