FileRush has a torrent file and FileShack has a direct download. For some odd reason EA has asked FilePlanet to hold off from putting the file up, so they won't be hosting it for a while, but that won't effect most of you.
EDIT: After playing it for a few hours I can confirm that I will not be buying Battlefield 2, I might go into this in a post in the future because there are a few games that do this one thing with player tactics, but it is certainly not my kind of game.