The ZenZui interface is based on tiles. Viewing a youtube posting on the main web site for the launch helps quickly illustrate the interface and it looks pretty cool and utilitarian (from Microsoft no less). The best part is that the interface is free and is aimed to work with most platforms.
I applaud this innovation. My current MDA via Tmobile works quite well but like most cell phones the browser is slow as a slug. On a related note, I highly recommend the bluetooth device available from Plantronics which is the Plantronics Discovery 640. I purchased this unit for $120 right after it came out last year and the 640 works flawlessly for me.
The volume controls on the earpiece are flush with the tubelike ear piece but can be quickly located and adjusted. The set comes with a small case for most model interface connections and a sweet AAA battery instant charger along with the AC adapter.
The quality of sound is the best I have used in my cell phone usage too. Check out Amazon pricing here which at $58 is a steal.