550EXand580EX II in Combination Question

Greetings - I have grabbed coffee and perused the threads a bit. I just bought the 580EX II this weekend and have the 550EX. Can I assume using the 580EX II on camera as master to trigger the 550EX as slave is the preferred set up? I am shooting on 5D. I have not shot anything master/slave yet (580EX II is just out of the box), but assume no other accessories are needed? If yes and yes to my assumptions above, I'll fire both of them up tonight. Now I need a lightstand to hold the slave!
Many thanks.

Doesn't make any difference except for ease of use, but i'd use 580 as master and 550 as slave.

I have both these flashes and have used them in different positions (master/slave) and there is not much difference. But one thing to consider is if you are going to use the off camera slave as your main light it will be working harder than the fill flash on camera. In that case you will be better off with the 550 on camera and the 580 as slave off camera since the 580 cycles faster and is a little better on batteries.

Thanks Tim & Ron - Tried 580 on camera and 550 slaved and they performed flawlessly.
Will try the reverse, and expect similar result. Good point about slave as main light - thanks. Just ordered lightstand from B&H with umbrella holder/shoe accessory. Most appreciatively,
John