[Mercantides]

He's a character in a book by Jack Vance. When I was creating an online poker account I just grabbed the book and kept trying names until I found an original one. Now I use it on all accounts and forums since I've never seen anyone else use it.

Edit: I just googled it and the only results were to posts I've made in online forums or my delicious account. Upon closer inspection it might not be such a good idea to use the same name in more than one place.