Let's try the classic "describe it as [insert_popular_company_here] but for [insert_difference_or_industry_here]" approach.  We've been been described as:

• Twitter with better geolocation support
• Yelp minus the really long reviews
• Digg for the real world (we like this the best because it's more about voting, though commenting is great too)

We're often asked why the world needs another mobile commenting application.  We've used several applications, including Yelp and Goodrec, and we've got a few complaints ourselves:

Mobile is meant to be fast!  Don't make me work hard to read or write a review.  In fact, let's throw reviews out.  In the day and age of Twitter, who needs em?

• While both Goodrec and Yelp both require you to register and login, we let you optionally set a username later and use Facebook Connect exclusively to hook you up with your friends.
• Yelp does not support voting, Goodrec requires 3 taps, we do it in 1.
• Yelp takes 5-6 taps to comment, Goodrec takes 3, we do it in 2 (seriously, how many developers pay this much attention to the number of taps you have to do?  We think we are bordering on OCD).

Data sets expire quickly (yeah that Peete's Coffee isn't on that corner anymore).  Much of the location data obtained through Google and Yahoo APIs contain oudated information. 

• We "cleanse" our data set each month -- over 100,000 old and outdated locations were removed from our collection in July alone.
• We let users flag walls (and comments) and they are automatically removed after a threshold is reached.

Fast and relevant.  Not a bad combination to start with.  It's also a fun app to use, especially if you liked foursquare's badges.  We have 70 badges right now.  And yes, they make for excellent pick up lines when you're at the bar ("yeah, I got that Mob Leader Level 5 badge--so what's your name?").

As for the real world test and stuff that actually matters, here is how you know if you belong in the graffitiGeo community (which currently consists of a few people):

• You love discovery -- you wouldn't care about this app if you didn't because it involves discovering places in your city.  You want to be the early adopter in a crowd and don't mind the "beta" sticker that comes with it--which means some features won't make sense, and some things just don't belong there.  You'll let us know, and we'll hook you up with the "Genius" badge for letting us know what sucks.
• You often wonder what places are good, but you're too lazy to sift through thousands of reviews (reading is for bookstores).  Maybe you found a place, but you can't pronounce half the stuff on the menu -- use the app to check out the menus sorted by popularity (we haven't seen this one before).
• You want to share hidden gems with your friends, and you don't have the patience to manually invite them to join some random application from the tens of thousands available.  We exclusively use Facebook Connect, so login once and you'll always be synched up with your friends.

Fit the profile?  If so, we are officially inviting you to join the movement for simpler and faster mobile recommendations.  Start here! (iPhone only right now, but we'll build more versions out if you request them).  Some of these features are coming in the next update, v1.2.  Currently, v1.1 is available in the app store, but we know there is quite a lot of progress to be made yet.

Reasons to use graffitiGeo

• You're both lazy and sophisticated; reviews are not for you, but votes and 100-character comments are fine
• You want to know what people are saying about the places you go
• You don't believe in extortion