We've seen waterproof phones in various guises over the past few months, but HzO WaterBlock is demonstrating some impressive technology at Mobile World Congress that might make its way into your next smartphone. HzO has several concept devices, including an iPhone 4S and a Galaxy S II, that are covered in a thin film nano-coating to provide a near invisible layer of protection for your favorite gadgets.

The coating is highly water resistant and HzO seemed happy to dunk various tablets and smartphones into a bowl of water today to prove its point. If you watch the video demo (below) closely, you'll even see how water droplets get trapped under the screen. The company isn't discussing which manufacturers will use the technology in future devices, but it has previously hinted that Samsung is "really excited" by WaterBlock. Either way, it might not be too long before you have to worry about dropping your smartphone in a beer, toilet or bath — WaterBlock could save the day.

Aaron Souppouris contributed to this report.