This is from my Face The Jury account! Does anyone know how to add a picture straight from your computer without hotlinking? I've tried a few times but it never works. I just end up with a big red "x"!
You can attach an image, with the attach button, but you can't do that in your sig. To have it in your sig it needs to be hosted somewhere, hipgalleries or photobucket both work well. Oh, and if you just want to test something, the 'preview' button works rather well for that.