Protip - Cars have medium to humongous blind spots. Don't endanger lives; always mirror AND shoulder check before pulling out. That way you won't have to face my wrath, ever.
A side note; filtering between lanes is legal in the UK if it is safe to do so, like crawling or stationary traffic. Doing it at speed is a little iffy, for you and the cars around you.
In other news, I hope to have my bike back on the road within 30 days. BOOYAH!