This is a tutorial / demo I made recently.

Magic Lantern ISO and FPS Override feature demonstration - YouTube

A demonstration of the use of ISO reduction and timelapse video features in Magic Lantern firmware for Canon EOS cameras.
You can get the firmware here: MagicLantern.fm - Home (http://www.magiclantern.fm/)

ISO reduction is a digital crush of luma values in the camera and will not completely replace the use of ND or Vari-ND filters, but is usefull if you have none available. Remeber that shots with white clipping will also require some color correction, as the red channel does not get clipped the same as the green and blue.

The FPS Override feature allows you to record video with much slower frame rates. Even as low as seconds per frame! This leads to over exposure hence the need for ISO reduction ;)

This video was shot on an ipod and edited in FCP 6.

Very cool. I'm excited about the FPS override. My first timelapse with the 60D was pretty ambitious - a couple hours later I'd put 7500 shutter actuations on my new camera! Wasn't successful in getting "silent" shooting to work in ML.

FPS override looks like a good solution to explore - thanks for the preview!

Yes silent shooting can be fiddly and your not sure if it worked ok until you convert the frames in post. I really think that FPS override, creating a full HD timelapse video, is a better solution. However best quality and most flexibility is found in a sequence of full frame shots. Better compression and color space, not to mention resolution I guess it depends on what you expect to do with the footage at the end.