I had a conversation with Yelp yesterday and they are looking for Android developers in Chicago who would be willing to jump the ship and move to San Francisco.
If you are interested please send me links to Android (and other mobile) applications you have created in Market and LinkedIn profile with your complete resume, recommendations in LinkedIn might help, too.
Please attach a cover letter explaining why you are passionate about the idea of working for Yelp (should not be hard).
looking forward to hear from you,
Uki D. Lucas