If I didn't get to self-righteously blow by all the cars waiting for lights I think I would leave my bike at home. That's the joy of the commute. I don't care that they'll pass me again later on. What I try to do is make sure it's surprising to them how far I got before they came up to me again. My hope is somebody'll say to themselves, Gee this driving thing really isn't much of an advantage, is it. Maybe I should ride my bike instead, too.
I do it on the right if there's enough room. I lane split on my Vespa, too, at lights if there's enough room. I laugh all the way to the front.