I searched for world of warcraft, and i just took this picture.
1. Save the picture you wanna use in your signature (duh)
2. Open the picture on Photoshop
3. Zoom in so it is easier to work with.
Go to the top of your screen and find the button called "Filter". Now, Find "Render" and press on "Lens Flare ..."
[IMGL]http://img528.imageshack.us/img528/9436/74684280mb8.jpg[/IMGL]
I places some lens flares on the draenei's sword, and a big explosion in the left upper corner.
[IMGL]http://img516.imageshack.us/img516/6985/92802398ub6.jpg[/IMGL]
Now, time for the blurred - fast running effect thingy.
Go to Stylize - Wind...
[IMGL]http://img515.imageshack.us/img515/916/17914630ao8.jpg[/IMGL]
In this picture it looks ugly :P (my mistake lol)
Now we can write something!
[IMGL]http://img515.imageshack.us/img515/5319/47529798aq5.jpg[/IMGL]
I guess that was it Have fun everybody. Show me ur results please