420ex question

Is there a way to make my 420ex fire as a slave simply by using another 420ex, or even the popup flash on my 10D? I have two 420s (I broke the hot shoe on one when it was hit by a soccer ball and never got it fixed). I was thinking of using the broken one set on its side ontop of the camera bag as a cheap way of shooting with two flashes. Is this even possible?

Sorry, you're out of luck here. You can only use a Canon flash that can be a master, like the 550 or 580 ex, or use the separate Canon wireless transmitter.

No, sorry. Even an optical foot slave is reported not to work well with Speedlite units. You need a master like the 550EX or 580EX.

does the 10D have a pc sync port? maybe with a optical slave unit and a pc cord. I have done this with great success. I have used a wein optical slave too, but it only really is reliable with my studio strobes flashing.