I came across mobimity.com, which is a new LBS app. The concept is quite interesting. It allows to browse for other users in close proximity, without sacrificing privacy. It is good to make new friends and also is useful to meet your friends who use this app. You can chat, post messages and make new friends using this app.
If you are interested you can download this app(which is in beta version) from a mobimity and start testing it. Currently its available only for win mobiles, coming soon on android, blackberry and iphones too.