I'm typing this on the second laptop I've ever owned, and the first one that actually shows the color red on the screen. I purchased an IBM Thinkpad R51e on craigslist for $150.00. There's nothing really special about it. It's a very solid machine, has a 2.6 GHZ Pentium M with over a gig of RAM, a CDRW drive, and a 15" screen. It does have a 4200 RPM, 40 GB hard drive, but I can buy a 5400 RMB, 120 GB hard drive for less than $70.00 new.
I bought this laptop so I can work in a variety of places without the need for my desktop, and I also bought it so I can use a computer without being secluded in my office. Also, with number two on the way, my office's days may be numbered. =) This configuration at this price works very well, actually better than I expected.
I also purchased the laptop to have a Windows installation when I need it, which is rarely. So the first thing I did was install Windows XP SP 2.
I then immediately installed Kubuntu. I was very tired and wasn't paying attention to what I was doing, and ended up installing Kubuntu in partition that was too small. It took about an hour to fix that using the GParted live CD, which consisted of mostly waiting. After that, I updated Kubuntu, and low and behold, everything from the wireless to the sound to the display worked. And it worked well. It has excellent power management and steps the processor down when on battery. It has several default profiles which saves battery life by dimming the screen among other actions. Linux tends to work very well on older hardware. The entire process took about two hours.
I then went back to the Windows installation only to find that, aside from the basic video, nothing worked. No networking, not wireless or cabled, no sound...nothing.
After I used Linux to download the networking drivers from the website, I was surprised to find I couldn't connect to my wireless network due to the lack of WPA-PSK support in Windows XP SP 2. I couldn't download the update, or SP 3 with Linux because it wasn't a genuine copy of Windows.
Luckily, I was able to use the neighbor's open wireless connection to download the update, then update Windows and install anti-virus software. I also installed the remainder of the missing drivers.
It took me around four hours to fully install Windows, and it would have taken me less than an hour for Kubuntu if I hadn't screwed up the partitioning wizard, an admirable feat being so easy to use. Still, it took me half the time even with that set back.
Also, the default installation of Windows SP 3 and anti-virus is 8.2 GB while the default installation of Kubuntu with the openoffice.org office suite, two browsers, advanced PIM software, DVD and CD Burning software, and much more is 2.9 GB.
I updated Windows and haven't booted to it since. If (when) I do end up getting a Kindle, my Linux installation will get more disk space. =)