Protective apparel and equipment designer has teamed up with to release two new, rugged iPhone 4 cases. The ($25) takes its inspiration and design cues from the rough and tumble . The case is made from high density, shock-absorbing silicone and boasts an anti-static coating that keeps the silicone soft, sleek, and free of lint and dust particles.

The ($35) is a hardshell case with a silicone core that boasts a rugged yet stylish design. Textured bumps provide extra grip, while strategic cutouts allow full access to all your device's ports.

Some activities are more punishing for your iPhone than others. For instance, it would be unwise to go mountain biking with the same kind of case you'd use at a dinner party. Ballistic's ($30), which will be available come January 2011, lets you adjust its level of impact protection to meet your specific needs. The slim TPU-and-silicone case features ballistic corners of varying levels of thickness--you can swap the corners as desired. Though this approach won't appeal to everybody, for active iPhone users, it could prove a convenient way to crank up your device's protection when needed.