I own both. I have one of the new macbooks (not the pro) and I also have a lenovo T61. The mac is definately consumer grade the the lenovo is a business class machine. I paid about 1200-1300 for the mac and the lenovo was about 1500.
I run the new Mac OS and also I run Vista enterprise. For work purposes, the PC is far superior. Office for Mac is okay, but is not Office for Windows. however, for pure day to day use, the Mac offers web browsing, email, and IM. (I mean, what else do you need.)
For photos, the Mac's simple iPhoto does an excellent job. For music, itunes is also a great app (though it is exactly the same on the PC).
One thing about the mac I love is the blutooth stack. The windows blutooth stack sucks right now (hope it gets fixed). Macs kicks butt.
Games? Well, I can run simple games on both. Unless you buy a huge laptop, which no one in their right mind does, you can't run games that well anyways.
That brings me to size. The macbook is like a itty bitty computer, but it's dense. It's too heavy for what it looks like. The lenovo is larger but weights less, even with the extended battery. However, the form factor for both are excellent.
Screens? Well, the lenovo is a 14" and the mac is a 12". Most business PC's will have a matte screen, and only the macbook pro comes in a matte version. (You will pay the big bucks for a macbook pro, but if you do, GET THE MATTE SCREEN). Why do you ask? Well, have you seen the difference between plasma and lcd? yeah, reflections suck. And when you're mobile, you will get light coming from all over.
This is my two cents. I have no bias to either, I love them both. But they have their drawbacks. I thought I'd give you the stuff that only someone who uses them both on a daily basis for hours would know.. good luck and if you have any specific questions, PM me.
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I've got spurs that jingle jangle jingle.
As I go riding merrily along.
And they sing, "Oh, ain't you glad you're single?"
And that song ain't so very far from wrong.