Wikis like this TWiki are a good medium for a transparent computational lab notebook.
The reason is that TWiki offers time-stamped RevisionControl via RCS.
RevisionControl means that, while it is possible to delete or modify most pages,
a complete record of all changes is maintained.
(To view the history of a page, click on the "Log" icon that is (probably) at the top right of your browser window.)
-- IanHolmes - 28 Nov 2005
Here are several of the better instances of the site's use as a notebook: