I always wait a week from the date of the interview, and if i havent heard back yet, then i make the call. That way its long enough that you don't look too desperate, but they know that you are definitely interested. Kinda the SWINGERS date method, if you've seen the movie

. I also call a week after leaving my application and resume because Ive been told by interviewers that when you talk to them, they always pull your resume from the stack to look at it, and then place it on top after the call.