I had no idea Foursquare's API had matured so much, loads of opportunities to build interesting things. This write up has some great insights into some of the challenges of implementing against it.
Yeah, the connected apps thing really is a joy to integrate with. They've had the push API that sends you checkins for a while but they only added the in-app integration points a couple of weeks ago, and it's those that make the whole thing really interesting.
+1 It looks really cool, I just hope it doesn't end up like Twitter...
"Step one: matching up the venues" - for your interest Bopgig uses a Google search on foursquare.com to obtain venues, seems to work decently and is automated. The 4sq api seemed to return too many errors when last tested.
I've been using that technique (site:foursquare.com name-of-venue) as a backup, but we've been taking the opportunity to fix obviously incorrect lat/lon data on our venues at the same time so we avoided full automation.
We're you scraping google for that, and did you have any problems with that ? (i.e. Google tend to block automated queries)
I normally just provide the human who's going through the crowdsourcing interface with a link to that search on Google in a new window - no need to scrape anything if you do it like that :)