If you're shooting video with your Canon 550D or 60D you should definitely check out the Magic Lantern firmware. It will give you much more possibilities to adjust the settings on your camera.
I installed it today and it really blew me away! It is great!
What i liked most:
- turning off the AGC
- on screen audio meters
- live view zebras !
- on screen cropmarks
- built in intervalometer for shooting timelapses !
- custom (native) ISO steps !!!
- custom shutter speeds !!!
- kelvin white balance !!!
- DOF "meters"
- higher bitrates !!!
These are all the features that I missed on this camera (but there are many more). So if you're interested in "tuning" your 550D or 60D check http://magiclantern.wikia.com - and please consider a donation if you like it.
Here's a nice video by Matt Dennie that demonstrates what the new firmware looks like:
My rating 5/5.