Ace For Men Nail Brush ($8 @ Amazon.com)
If only there were a tool that cleans and scrubs your grungy nails after a hard day of doing something extremely dirty, and that also looks like brass knuckles? Oh wait, there is! This thing does it all: It boasts a 360-degree scrubbing ring that removes paint and grease from the surface of your nails, and a cleaning pick that removes dirt from underneath them. A nail file then smooths things out.