Personally, as a driver and pedestrian, I used to get annoyed by cyclists riding on the pavements, particularly the one or two arseholes who either ran into me or rudely shouted to get out of the way.
But then I started looking at the roads they were having to cycle on in the mornings and evenings, and to be honest, if it's a choice between me sharing the pavement with a cyclist, or a greater risk of someone going under the wheels of a truck, then that's fine by me.
That said, cyclists who cycle on the pavement (and I'm including the idiots who thunder down the canal towpaths every evening) need to respect the fact that pedestrians have right of way on paths, and cycle carefully and courteously.
I would also like to see some sort of government sponsored training scheme for anyone who cycles in London, to demonstrate they understand how the rules of the road work, and also to teach them stuff like how trucks corner - i.e. that big space you're aiming for on the apex is going to get very small very quickly.