Foursquare Realtime API when someone checks into a venue

I multiple venues and I'd like to receive a push notification for when user(s) check-in. For example, the web site will display a message: "4 people checked-in to the LA Fitness". I'd like the results to be in realtime so the site will constantly be updating. I've looked at the Fo开发者_如何学Pythonursquare API and couldn't find anything realtime and updating.

Can this be done in PHP or nodeJS?

Yes, this is definitely possible. Foursquare released a Push API at their last hackathon (Edit: March, 2011). You may have to email the support team to get access, but they're very accommodating people and I'm sure they would love to hep you out.

Also, here is a link to an example consumer written in Python:

https://github.com/nsanch/foursquare-push-api-sample

P.S. For anyone interested, here is the article on the hackathon and the Push API

http://blog.foursquare.com/2011/02/22/stop-hacker-time/