What sweet stuff could foursquare choose to do with its funding??

With foursquare closing its round of funding, I was wondering what the HN community thought that foursquare could do to innovate and cross the chasm into a more widespread adoption (especially with Facebook looming). All us early adopters love it, but are there any cool ideas they could play on? LooptStar is doing some interesting things with getting into the loyalty rewards before foursquare? What if they applied some Groupon like tactics into foursquare?