The Tokyo Institute of Technology is working to improve touchscreen input with a range of haptic adapters. The adapters, which can be attaced to your thumb or held like a brush, look pretty straight forward and I wouldn’t be surprised if these went from research to production overnight.
In this video, a researcher shows how the silicone adapters can provide a much more natural human interface. An adapter with a ball allows for more natural movement in video games. A brush-like adapter allows him to ink Japanese characters naturally by adding pseudo pressure sensitivity to an iPad.
The beauty of these adapters is in their simplicity. No fancy drivers, digitizers or batteries required.