"... the easiest way to update an existing node.js (ubuntu) installation? ..."
The latest vid from ryan ~ http://blog.nodejs.org/2011/03/17/welcome-to-the-node-blog/ explained the need to download & install from source. This presumes you have V8 installed. Holler if you get into trouble I've installed a few times on Ubuntu 8.04 Hardy Heron.
"... You mean, he explained that it was necessary to build from source, and why? Is this information available in textual form? ..."
It isn't 100% necessary. You can install from binaries. But as node is a moving target as a dev you get the best feature set/bug fixed version, faster. The talk hasn't been transcribed to my knowledge. Why not view the vid or ask @ryan or irc://irc.freenode.net#freenode why from source? The install instructions here ~ https://github.com/joyent/node/wiki/Installation or install binaries here ~ https://github.com/joyent/node/wiki/Installing-Node.js-via-p...
The latest vid from ryan ~ http://blog.nodejs.org/2011/03/17/welcome-to-the-node-blog/ explained the need to download & install from source. This presumes you have V8 installed. Holler if you get into trouble I've installed a few times on Ubuntu 8.04 Hardy Heron.