If you mean for your avatar, or something, it's fine. You can use any image you want, provided the site allows offsite linking. Many players use pictures of actors or something like that anyhow. (:
If you find a picture you like, it is usually best to save the picture to your computer, modify and resize it as you see fit, then upload it to your own server to host it. There are some free hosts out there, I think Photobucket is one of them, that allow you to host pictures.
There are a few nice people in the combine that will host it for you as well.
____________
"Somewhere, there's a bullet with your name on it. The trick is to die of age before it finds you"
i finally got a sig up and want to change my picture on here to match it but i think they cropped it or something to get the right stuff in anyways i was just wondering if i could get my pic changed from a Kel Dor to this guy.