Foursquare recently announced that its Pages program is open to all. All you need is a Twitter handle and you can publish Tips (a/k/a "Content") to Foursquare users who check in to a given venue. For example, NASA publishes this Tip to those who check-in at the Cal Academy of Sciences :
The only place on Earth with an aquarium, a planetarium, a natural history museum, and a 4-story rainforest all under one roof! The Morrison Planetarium is the largest all-digital dome in the world.
Publications and organizations can now push content to places (in addition to publishing to the web, RSS, a mobile app, to Twitte, Facebook, etc). This is pretty frickin cool and an interesting way to think about evolving a Publisher's relationship with its readers. Let's say you publish a site about coffee... why not create a Foursquare Page, encourage your readers to follow you on Foursquare and then regularly publish Tips about local coffee shops, perhaps offering suggestions? This really turns content into a service. This could evolve in very interesting ways for Foursquare and the publishers who participate. What if Tips could be pushed to certain types of users? What if they could include links? Then Foursquare Pages becomes geo-based acquistion, turning venue visitors into readers.