One of the nice things about Linux is that you can take an old laptop and make it new again, at least as far as the software is concerned. I took a pair of Mitsubishi Amity CN subnotebooks, very small 133MHz Pentium machines with 48MB of RAM, and installed Damn Small Linux (a/k/a DSL) on them. They now run modern lightweight apps and a version of an operating system that is being actively maintained and developed.
There are at least half a dozen mini-distros I could have used. My favorite, Austrumi, sports a 2.6.14 kernel and a really well thought out desktop but lacks wireless support, something I want on a laptop. DSL still runs a 2.4.26 kernel but it does have very decent wireless support and a fair selection of applications, both as part of the core 50MB distribution and as extensions, packages easily added onto the core system. I could have gone with the brand new DSL-N and had a 2.6.x kernel but none of the extensions have been updated to work on it yet. DSL extensions offered in .uci format (Universal Compressed ISOs) allow me to add apps, libraries, and development tools while still conserving what little RAM I have.
Probably the best thing about DSL is their frugal install, basically a Knoppix poorman’s install where the 50MB iso image is run much the way a live CD would run but with the speed of a hard drive. It also loads as much as it can into a RAM disk and surprisingly that works out really well even with only 48MB of memory to work with. Frugal is more than just poorman’s: It boots directly from grub or lilo with whatever options you need for your hardware, and, perhaps more importantly, allows for persistant /opt and /home directories, allowing you to drop in a new version of the OS easily while preserving data and add-on software. It’s also nice from a security standpoint since the OS lives in a read-only filesystem and executes from RAM.
The net result is that my ancient little laptops are actually pretty fast at most things and actually very useful again.