At first glance, it looks like a Cell phone but it'sn't one. It's a Cellphone flask to carry water in "geek" style.  Made of stainless steel, the cellphone flask carries about 4 ounces of water and is about 5" long and includes a leather belt holsther for a price of about US$13 from here.  To drink water, just unscrew the antenna!

Of course, if you are carrying a cellphone flask like this  or know some one who is, you know who the geek is.