On Wednesday I used another advantage of digital cameras, the white balance. I was visiting some family and did want to use my flash (Canon Speedlite 420EX), but I don't like direct flash, so normally I use the ceiling to flash indirectly.
With an analog camera this wouldn't have worked there, because the ceiling is a wood knock-off and by that brown. But this is no problem with digital pictures if you adjust the white balance accordingly. You could do this later on your pc, but using the Canon EOS 20D is much easier: just use the manual white balance. For this you have to take a picture of a white object. Using this picture the 20D can calculate a white balance setting. Select this one and you get white without any further work. ;-)
To demonstrate the effect have a look at the image below. The first stripe was shot using a direct flash, the second flashing indirectly via the ceiling with automatik white balance, the third stripe is the white object (a door), and the forth it the bouquet again using the manual white balance got from the door image.
<%image(misc/manualwb.jpg|500|313|Manual WB)%>I think this is quite impressive. Esp. as this is a very easy and fast solution (if the colour of the reflected flash doesn't change depending on your position).
