Earthcomber is an interesting location-based service that bills itself as a "personal radar", providing an organized list of events and entertainment in relation to where you are. Just type mobile.earthcomber.com on your iPhone (Earthcomber will work with ANY web capable mobile phone) and Earthcomber's server will detect your locale. From there you are provided with category-based list of services such as Food, Music, Movies, Recreation & Sports, Adult Entertainment, etc.
The service works really well, based on my own testing. Not only did it correctly identify various entertainment venues in my area, I was even provided with basic mapping and driving instructions as well.