My office is completely Windows-based, as is my office computer. I needed a new laptop for travel a few months ago, and I bought an iBook when I looked at the windows offerings and was unimpressed. I use it for Word, Excel, Powerpoint, and general e-mail/websurfing, and I've never run into an incompatibility. If you prefer the Mac and don't depend on any specialist windows-only applications, I see no reason not to get one.