I use the ST-E2 to trigger my strobes. Only thing I need to do is tape the four pins that form a square underneath that turns off the E-TTL pre flash output otherwise the stobes fire earlier than the camera expects for exposure. So instead of getting the flash-flash you just get flash and not a black frame. Hope that makes sense.

If you have the 550EX you can use that as well, just turn it down to it's lowest setting for output, again I would suggest taping the four pins that form a square (there are 5 pins) and try it.

The only previso to all this advice is that the three monolights have a photocell that detects when they need to fire.

I do this, but I also have a cable sync attacted to one light now and have the other fire using the photocell (I have Bowen lights) and that way I ensure that I don't get a misfire as well. You need to have a Safe-Sync connection for the cable if you go that way as most monolights sync voltage will be too high for the 10D (long story). Wein make them I have one works well, although there have been many that have problems.

Either way I have described works.