Street Fight Daily: 04.19.11

A roundup of today’s big stories in hyperlocal media, technology, advertising and startups

Groupon is buying Pelago, maker of local discovery app Whrrl, in a bid to improve its ability to bring together consumers and local discount offers. This could also mean a broader direction for Groupon as it looks to expand beyond daily deals to more mobile and personalized discounts. (GigaOm)…

LocalResponse is a “social advertising platform” that lets small businesses sift through the stream of public check-in and review data to see who their most loyal customers are, and send them coupons and messages on Twitter. (NYT/Bits)…

Foursquare has added a feature that will bring some context to your historical check-ins. Now, when users look back at their check-ins, they won’t see only their pictures, but also pictures taken by friends who were also checked in at the event. (ReadWriteWeb)…