While becoming the 2008 Scrabble champ, I was able to try out my friend's iPhone which has a drum beat sequencer. I was very impressed by the user interface, it really makes full use of the touch capabilities.
I had previously thought that the iPhone was a disaster, I now can see, or feel, that its a quality item. I still like my e815 (which I really should get reactivated) too much to think about getting an iPhone, but if iPhone apps like the drum beat sequencer are available for the iPod touch, I might think about getting one of those.
The app only cost $4.99, which is a great bargain in my opinion.
NOTE: Its very cool that linux has been ported to the iPhone as well!