It was a stroke of luck that my Canon 550D/T2i is one of the supported platforms for Magic Lantern, a firmware add-on. Although initially created for shooting video, a broad array of features have been added for photographers.
I took the plunge this weekend, downloading Stable Release v2.3. I formatted a spare SD card and copied over to it a binary autoexec file and the FIR file for my camera model. The first attempt to load the firmware failed. Following instructions, I re-applied the Canon 1.0.9 firmware and tried again. This time it took.
One of the amazing things about the Magic Lantern firmware is that it does not replace the stock Canon firmware. It runs alongside it.
The hardest part was figuring out how to use the new features. My killer app was the automated focus stack. It probably took an hour of experimentation before I finally got it right. With the camera on a tripod, I start in Live View, which seems to be an essential aspect for using Magic Lantern. After focusing in on a starting point, you enter Magic Lantern by pressing the Trash button on the camera. This brings up the Magic Lantern menu. From there, I go to the Focus menu and select Focus End Point. This takes me back to Live View, where I use manual focus buttons to set the final focus point for the stack. Back once again to the Focus menu of Magic Lantern, and I start the Play mode for Focus Stack. From there, the firmware takes over operation of the camera, shooting the series and changing the focus with each shot.
Here's one of my better results, taken with an eight-shot sequence:
This shot is actually a small portion of a much larger picture. I just liked the composition of this little group. I don't know what the flowers are, but they are quite tiny, somewhat resembling yarrow in size.
Magic Lantern is going to open up a lot of new possibilities for my photography!