Can I automatically check in to Foursquare?
Tasker can do it, using the foursquare API and the HTTP POST task
In the http post task, fill out the form as follows:


Server:port -> user:pass@api.foursquare.com
Path -> /v1/checkin
data -> 
vid=362349
private=1
facebook=0
twitter=0


vid is the numeric id you can get from foursquare.com by looking up the venue. I have it set to not share auto checkins with others. You can also use a tasker variable for VID and define the VID from other events.. IE, I have my office assigned by 'cell near', same with the park where I walk my dogs.. I just call the named tasker task and it checks me in when I get to that location. I follow it up with a 'Notify' action to let me know it checked it, and what venueid (this was mainly for testing..) You will want to use a phone number login for foursquare, not a emailaddress.. the @ sign in the email will confuse the http post function.