With a wlan stick, a battery pack, and Pure Data the Raspberry Pi becomes a swissarmy knife for MIDI and OSC.
In an ongoing project to make wearable non-standard musical controllers we found the vmeter which is a nicely sized touch strip with the one drawback that it is a usb device and as such wired. We looked into ways to make a wireless usb or MIDI connection or anything similar and found close to nothing that suited our needs (battery powered, small, flexible). After thinking about this for a while it occured to me that building our own system actually should take close to no hardware hacking and only a little software tinkering. So we decided to build our own. Basically a Raspberry Pi with a WLAN stick and a battery pack is all you need.