Using iPad and iPhone/iPod touch together

[Anorton]

I'm getting an ipad2 soon and would like to use my 3rd generation iPod touch as an instrument apps/Mikey2 processor for real time recording. I know I will be able to use the iPad as the processor and iPod touch as the recording hub via the line in on the Mikey 2, but I'd rather do it in reverse (most of the time). I'm hoping there is a cable/adapter I can use rather than another expensive interface. Any and all suggestions are appreciated. Thanks!