phoneman,
With the agreement of the CAA, you can claim P2 time in a (usually) single pilot aeroplane, if you are making a serious contribution to the flight. However I'm not sure how much convincing they will need if you are P2 on a C152 from Waltham to Wycombe and back.
Read up on it in LASORS which you can download for free here
http://www.caa.co.uk/application.asp...detail&id=1591