I recently spent some time experimenting with this very cool software and I've created the video below to show you just how easy it is to use.
Bottom line: Amazing interactivity, easy to use. No jailbreaking required.
Where to get the Apps featured in the video?
Audiobus (v. 1.0.21 reviewed)
Figure (v 1.4 reviewed)
Loopy HD (v. 1.4 reviewed)
Amplitube (v. 2.9.6, amplitube Free reviewed)
djay (v. 1.6.4 for iphone reviewed)[divider] [/divider]
See the audiob.us site for the constantly growing list of apps that support this technology.