Anyone use their router on metals?

Another newbie question. I know this is general routing under the general woodworking section but didn't know where else to turn. I did a search on google and couldn't find any info so I thought I'd ask you guys. Would it be possible to use the router on metal, maybe a soft metal like aluminum. Have any of you guys tried it? From the little that I found I guess you need an "end mill bit"? The problem is the end mill bits I found all had 3/8 " shanks. I guess they weren't meant for hand held routers. If someone can shed some light on the whole "routing metal" topic I would appreciate it. I wonder if a carbide spiral bit would work.