Waveboard is already live for Mac desktop, but an iPhone version of this Google wave client is yet to go live. This simply takes away the hassel of launching wave via a browser and retains the same layout feel for now.
Just like you use say tweetdeck and Gtalk on your desktop, this is Wave Board for Google Wave. I would be interested in seeing how it develops in future versions though. For the moment, a video demo of how it would look on the iPhone or iPod touch once live. (Of course, you have that little hack to get the Google Wave working on iPhone as an App!)
Get waveboard here