I've had some good experiences in the past with Crunchbang, a lightweight linux distribution, so when a new version came along I thought I'd have a go at building a VM on virtualbox to see how it went.
Previous versions have been based on the Ubuntu kernel, but the current version is based on debian - debian squeeze to be exact.
There is a choice of window manager - Open Box or Xfce. Of the two Open Box is a bit more minamalist in style. Xfce is the same window manager as is found in Xubuntu, has a slightly less hardcore feel, and which I used successfully on my old ppc imac when I was playing with some things.
The website gives you a choice of downloading an openbox iso or an xfce iso - unless your target machine is very tight for disk space it doesn't really matter which you download. Likewise, most machines, including those a few years old which are in their second or third incarnation, will have enough memory these days to run either window manager.
I chose the open box version. The text based install worked well, nothing really confusing, and in the most part taking the default option is fine. The only little gotcha I found was that if you set your preferred language to 'British English' by default you get a UK keyboard map.
Here in Australia, while we're closer to British English than American in usage, we do use US keyboards. However it's a trivial post install fix.
The first time you boot into Open Box you get the option of running a post install script to install various options not installed by default, such as Open Office, Java Runtime support and Xfce as an alternative desktop. If you install Xfce, you can of course change it to be your default if you don't get on with Open Box.
A nice touch, given that Crunchbang could well end up on netbooks (there is a special netbook install for the Eee available) and old laptops taken travelling - for example before netbooks were widely available I used to take an old macbook when going to wilder places on the basis I wouldn't be too hacked off if it got stolen or broken - is to also provide an optional install for dropbox.
That way of course all your valuable content can be synced painlessly to your main machine. And of course dropbox can be used to allow people doing things like research in libraries to again painlessly sync content across machines.
Given my experiments with Evernote, the syncing muliplatform notebook application, I thought I would install the latest version of Nevernote, the open source alternative Evernote client.
This just worked. A minor annoyance was that under Open Box it didn't add itself to the applications menu, but it did so under Xfce.
The only surprise with Crunchbang is that the default browser is Chromium - essentially an open source version of Google's Chrome, rather than the more common Mozilla Firefox. Wikipedia has a good article on Chromium, and if it doesn't work for you, installing Firefox should be straightforward.
So, impressive. Impressive enough to try on a 'real' old machine, such as the old (2000-vintage) Toshiba satellite that used to be my work machine and still has Windows 2000. Given it's gathering dust and hasn't been powered on for two or three years, it would probably give it an option to go out in a blaze of glory ...