At: ashok.org.uk/computers/porter
An Asus Aspire One (GZ5). It came with a cut-down, idiot-friendly version of Linux which I have replaced with Ubuntu 2008.10, which has been remarkably snappy.
Named for Fuller's fantastic London Porter, as it's easily carriable. (Anchor Steam's Porter may be even nicer, though - they're both fine beers).
porter is always the name of the most portable proper computer I use. The previous incarnations were a
Sony Vaio PCG-C1VFK (which ran Gentoo and BeOS) and a first generation Black Macbook (running OS X, naturally) that some bastard nicked, with a little unwitting help from the police.