PubSubHubbub. Say that three times fast. If you're not familiar with PubSubHubbub, it's an extension of the RSS and Atom protocol that allows the feed to push content out when it's updated. That's just the sort of technology we should see from check-in APIs like Foursquare and Gowalla.
Web and iPhone maps provider CloudMade can add a few more platforms to that list. Today it acquired German geospatial company One Step Ahead to incorporate Android, MeeGo and other mobile platforms to its suite of developer tools. CloudMade will also incorporate One Step Ahead's offline/online map technology, which passes a few map updates at a time.
Data marketplace InfoChimps continues its march to API-ify its most useful, sliceable datasets. The latest is a bundle it calls the InfoChimps Geo APIs and it makes available some extremely interesting location data from both public and private sources. The company has created a location data schema to unify sources, which include several place databases, Wikipedia articles and Zillow neighborhood boundaries.