Super Meat Boy boss strategies

Have you all found any kind of cool tricks for the bosses? I've found two so far:

[Worm Boss]
- On the worm boss there are the saw blades on either side of you with the platforms on both side rising and falling, however, with well-placed jumping, you can jump THROUGH the saw blades on the left or the right side. You need to jump between the bottom saw-blade and the one just above it. In this area, they can't hurt you except for the occasional larva missile and they seem to jump more often when you're in here.

[Dr. Fetus, light and dark world]
- On either light or dark version of Dr. Fetus, if you're quick you can actually outrun the saw blades that stop you from progressing too far. If you make it through the first portion very quickly, then wall-jump up onto the http://i.imgur.com/08UxZ.png, and then jump over the saw-blades you can make it over them and then continue through in a much faster way.

Anyone else have any tips for people trying to beat some bosses or just trying to beat them in new ways?