Once a month to process payroll in Sage, who, typically of any company with more power and money than sense, don't have a Mac version of their software
Windows in a VM is perfect for an otherwise all-Mac business that needs the odd Windows application.
Came back to Apple in 2006 after an 8-year hiatus with pc's. Love the iMac and software that came with it. Needed a better desktop publisher than Office for Mac, as it lacks Publisher. Got Parallels with Win XP and Win Office up most of the time. Outlook beats Apple Mail, but that may change with Leopard.
I usually only boot windows when I need to pcAnywhere into my work computer, but now I installed pcAnywhere v12.1 and they have OS X support for both the client and server so I don't need Windows anymore for that.
I'd think I use each about 50/50. Windows is a must for emulators/games. It also seems whenever I need to do something alittle more complex I must use windows to get the proper apps. Not a fault of the OS just not nearly as much underground developer support. Use OSX for day to day stuff and work (ProTools).
However, I'm hoping to get a new Mac in the next 6 months, and that will definitely have Windows on it. I imagine using VMWare as my ideal solution, and am looking forward to it greatly. I imagine using it probably 5 days/week.
When I switched about a year ago, I used Windows apps. (via Parallels) on a daily basis. Since then, I have transfered my database to Address Book and I don't use Windows anymore.
I do, on the other hand, have a PC that I use exclusively for gaming.
i have to go to windows everyday because i can't really afford the new software. i switched on a whim after investing heavy in expensive adobe bloatware (CS3) and what to do? the biggest problem is that parallels does not support firewire, so premiere as a convergence app is a no go there. well, at least i am coming up to speed with FCP
I'll let you know as I have a tonne of stuff designed for Windows including Adobe CS3 stuff and Expression Studio stuff. These are taxing applications an I'll see how things go on a Mac Pro and Boot Camp.
I use my bootcamp partition every now and then...
there is some software that I use for uni and is not available for the mac...and for occasional gaming (once every week or so).