I'm off to do some shooting tomorrow and one of the things I wanted to do was figure out how to shoot the cool low DoF stuff you often see in tricked out video.
So I searched and came up with this:
http://vimeo.com/groups/canoneos500d/forumthread:8176Which is an outstanding bodge which should work really well with the 50mm prime, for some moody pre-race footage.

Just tried it out and it works like a charm, too.
Another thing worth noting is that on the Canon IS stabilised lenses where you have Mode 1 and Mode 2 you need to switch to Mode 2 if you're panning, as it stabilises in one direction, so you won't get the slight jerkiness I got on my Salisbury Plain video.
Post anything else you pick up in here.