Just wanted to shortly to write about nice app for max/msp users with iOS device:
Basically c74 lets you connect your iDevice with max/msp in a very easy way.
No need to know any objective-c or cocoa touch. You create your screen layout for iDevice in max/msp,
and then c74 external object creates it in your iDevice. Nice and easy.
It took me arond 30 minutes to make iphone controlled 4*4 led matrix using c74, max/msp and arduino. So its really powerful and easy combination. It is also possible to use idevices sensors to collect data and also possible to send data to iDevice.
Only major drawback s that it requires wifi. So no possibility to control something over 3G. But otherwise very nice little app I can recommend!