Yet again we've run into another iPhone app that requires you to have a good deal of friends who have an iPhone and use the same app to gain any benefit out of it. Whrrl for the iPhone utilizes GPS to pinpoint where you are and show all the locations around you that fall into one of the following categories: Restaurants, Happy Hour Now, Shopping & Retail, Open Now, and I've Not Been There.
Unless you're in a major city, you'll find that the map function isn't that useful. The map will have pins on it showing what's around you and whether or not it has been rated. The list function shows you what you're searching for in order of closest to furthest away.
Under each listing there's a 0 to 5 star rating along with the category that the location falls under. Selecting the location gives you two more options: facts and opinions. From there you can read anything written by your Whrrl friends, notify them that you're there, indicate that you want to go there, or that you've been there.
Overall the app doesn't offer that much to what already exists for location/review apps for the iPhone. It suffers from the need to be friends with the people visiting or reviewing the locations around where you are. Unless your friends all have iPhones and all happen to live near you or where you want to travel, you won't really gain anything useful out of it.