For motorcycles, filtering at stoplights is accepted and expected practice pretty much everywhere in the world except the 49 US states that aren't California. Traffic engineers generally agree that filtering and lane-splitting *reduce* congestion, by reducing the amount of roadway space that motorcycles consume -- every motorcycle that filters to the front at a red is one more car that can make it through on the next green cycle.
I happily filter on my bicycle. (I'd do it on my motorcycle as well, if I didn't think it would mean getting ticketed regularly.) I don't think it constitutes anything like "flipping off" other road users. Are motorists flipping me off when they pass me? Filtering is the same situation, but with the roles reversed.
I can understand sharing the misery when avoiding it would mean heaping undue misery on others. But I don't think that's the case here.
Last edited by YoungerNow; 08-07-06 at 05:29 PM.