sustrans is working on some routes for cyclists and pedestrians in london boroughs of enfield, haringey, hillingdon, ealing, harrow, hounslow, and brent.
GOAL - Greenways for the Olympics and London there's info via the link above, including the opporunity complete feedback questionnaire(s) - tho you need to do so by the 6th march 2009 for the 'north west' area study, and 20th march 2009 for the 'north central' study.