Actually after a lot of research and internal debate, I think I've come to a frugal solution for my work computer: I'm going to buy a Windows desktop, and keep my ThinkPad just for travel or the rare occasions when I travel or want to work outside the office.
Buying a copy of Windows XP Pro to install on a Mac (I don't want to use Vista, I've heard way too many horror stories and my company is sticking with XP for the foreseeable future) would set me back $600 Canadian. I can buy a nicely equipped desktop PC, that is 4 times faster than my laptop, for less than that. And I already have a monitor that I can plug it into, because I use my laptop as if it were a desktop machine (I keep it plugged into a monitor, mouse, and keyboard).
This saves me a ton of money, because the alternatives I was considering were to either 1) buy a new 15" MacBook Pro with a 160 gig hard disk (to accommodate both my Windows work and Mac personal files), plus Windows XP Pro, all of which would cost me more than $3,000 Canadian, or 2) replace my old ThinkPad with a new Core2 Duo one with plenty of RAM and hard disk capacity, which would cost me at least $2,000.
I'm planning to buy the new (and incredibly ugly
) Lenovo A61e desktop when it comes out next month. I'll keep my ThinkPad for occasional travel and for days when I don't want to work at my desk. And I'll use Microsoft's free synch tool, Synch Toy
to keep my desktop and laptop synchronized; it works on either XP or Vista. Most software licenses allow you to run two copies of programs, one on a laptop and one on a desktop, so I shouldn't have to buy any new software.
This solution doesn't solve my "computer proliferation problem" but it's a lot cheaper than any of the other options I was considering. My ThinkPad should still have several years of life in it so I might as well hang onto it rather than replace it with a new laptop.