It's a bit like tinyurl.com, but for Usenet messages. If you don't know what Usenet is, then you can stop reading — this site is not for you.
Every Usenet message has a Message-ID. You can find it out by looking at the message headers. It looks a bit like this:
Message-ID: <1991Oct5.054106.4647@klaava.Helsinki.FI>
If you want to link to this message, craft your link like this:
http://message-id.net/<1991Oct5.054106.4647@klaava.Helsinki.FI>
Easy, right?
At some times, there will be a small advertisement on the site, which helps cover running costs — but the site is not for profit — any excess advertising revenue is donated to charity.
It's easy enough to link directly to Google's copy of a message:
http://groups.google.com/groups?dmode=source&selm=1991Oct5.054106.4647@klaava.Helsinki.FI
However, if Google changes its layout, then your links might get broken. Message-ID.net promises to continue to using this link scheme forever and ever. (Unless it's completely unable to offer the service any more — e.g. the Google Groups archive disappears.)
Also, the Message-ID.net link is a little nicer to read.
Toby Inkster. See tobyinkster.co.uk.