I use this and slax as emergency boot disks
Damn Small Linux is a business card size (50MB) Live CD Linux distribution. Despite its minuscule size it strives to have a functional and easy to use desktop. Damn Small Linux has a nearly complete desktop, including XMMS (MP3, and MPEG), FTP client, links-hacked web browser, spreadsheet, email, spellcheck (US English), a word-processor, three editors (Nedit, nVi, Zile [emacs clone]), Xpdf, Worker (file manager), Naim (AIM, ICQ, IRC), VNCviwer, SSH/SCP server and client, DHCP client, PPP, PPPoE, a web server, calculator, Fluxbox window manager, system monitoring apps, USB support, and soon it will have PCMCIA support as well. If you like Damn Small Linux you can install it on your hard drive. Because all the applications are small and light it makes a very good choice for older hardware.