Any surface as a touch interface :
http://medea.mah.se/2012/05/diy-use-any-surface-as-a-touch-interface/
http://vimeo.com/43106290
http://www.instructables.com/id/Touche-for-Arduino-Advanced-touch-sensing/#step1

Simply awesome

A simple board with regulated output and USB-B connector.

Washable ?

Many many applications :
- less wiring / swewing for lilypad
- will allow multi-clothes inter-operations
- people - people communication / interactions

http://en.wikipedia.org/wiki/Near_field_communication
http://en.wikipedia.org/wiki/Body_Area_Network
http://en.wikipedia.org/wiki/Personal_area_network