Anyone have a 13", 15" and a 17" ??? If so what do you use them all for? Do you need them or enjoy just changing it up, lol. Looking in the Picture Gallery it's surprising to see how many people own more than one or two Mac's. Some photo's show 3, 4 even 5 machines - cool My two computers get used a lot, but three or four I'm not so sure what I'd do with them.