SSTL and GES are looking for CubeSat passenger payloads on this Lunar mission:
Orbital passengers e.g. nanosatellites and CubeSats which will be deployed from the Mothership and which will operate in lunar orbit
More here: http://www.goonhilly.org/lunar. The UK CubeSat Forum can help in creating new contacts for joint proposals, so do post below should you want to be involved!