Hey, so I had a take on the whole finding and communicating with people around you that are interested in the same thing, in this case bitcoin trading, while maintaining your privacy. Maybe you don't want to publicly identify yourself as a bitcoin buyer or seller. http://bit-list.appspot.com
, uses your twitter account to authenticate, but you can even keep that private from others on the site, by setting your nickname. To further protect yourself, once you are done with a conversation, you can delete the whole thing.
I just finished implementing private messaging and thought that was a good time to announce the site here.
There is a mailbox like thing you can create at any point on the map, I call these Drops. Anyone can leave a public message in the Drop. You and the sender are the only ones who can see a private message added to a Drop you created. You can permanently delete/burn your Drop at anytime. In the message of a Drop you create, enter in #hashtags to enable searching out by the hashtag. Bitcoin buyers enter #bitcoin-buyer. Bitcoin sellers enter #bitcoin-seller.
I would appreciate feedback, thanks.