[Gmail-Users] Retrieving the URL for a specific mail or conversation

Is it possible to get a URL for a specific mail/conversation in GMail?
something similar to the links that are used on the Google personalized
homepage with the GMail widget that open the mail in it's own page.

The reason I am asking is that I have a simple CMS and I would like to
be able to add links to specific mails instead of duplicating the data
in both systems. Obviously I would have to be already logged in to
GMail but this is fine for me as I always have GMail open in a Firefox
tab.

I know this can be done I just can't find any means of retrieving these
URLs through the GMail interface.

Any ideas/suggestions?