Among the many community friendly aspects of HIH you'll find the Graphics Forum, a place where you can swing by and show off any of your art-related coolness. With the advent of Halo Wars, SPOC again decided that the new content from the trailer would make great sigs, and he asked the GFX community to come up with their best stuff.

Even though the submission phase is over, voting is still ongoing in this thread till next Wednesday. Swing by and vote for your favourite Halo Wars sig, and visit the other aspects of the Graphics Forum while you're there. These guys are awesome!