jon: It is called damaged. I believe that it was removed from a "lucky coin" holder (one of those "keep me and never go broke" metal discs).
I agree with treashunt, encased cent. Notice the knob above "WE." (Likely where a split bezel joined.) Notice the "L" of Liberty has had the rim pushed into it.
A cent has a metal, plastic or pressed paper "collar" crimped around it, usually with some kind of "good luck" legend. Here's an example presently on EBay: When the collar is removed, the edge looks like the coin in the OP. Broadstrikes are very rarely really circular, as without a collar the metal spreads irregularly.
I just realized the pic may not be of your coin, merely a coin like yours. There is an error that resembles the pic somewhat. The "railroad rim" caused by a partial collar/ partial broadstrike. On the error coin, one side will look normal, the other side is, well a broadstrike. see also http://www.cointalk.org/showthread.php?t=25014&highlight=railroad+rim
you are correct this is not my coin.mine has this mark on the obverse about 3/4 around the edge, without the crimp at the 12 o:clock position and on the reverse, the edge is 1/3 like that mark. and the edge is concave as in the top and bottom stick out further i tried to get some pics of my coin sorry for the bad pics
I can't tell from the pix (too blurry) so you'll have to be the eyes. I did a search of cointalk and found http://www.cointalk.org/showthread.php?t=2279 Post #10 (Mike Diamond) describes how to tell the difference between an encased cent and a railroad rim. Quoted: "These are not partial collar errors ("railroad rims"). These are encased cents (lucky token cents) that have been removed from the surrounding ring. These coins will show: 1. An abnormally small diameter 2. Warping of the surface (seen here) 3. A concave edge, similar to the rim of a bicycle wheel without the tire (seen here). 4. Often a horizontal or sloping shelf lateral to a false rim that's pushed inward. A true partial collar error will show: 1. A diameter that's greater than normal next to one face. 2. A "step" on the edge where you make the transition from the collar-confined edge to the unconfined edge."
thank you that was very informative i think i have an ex encased cent i will throw it in the dented bin