[kingsinger]

If you are on a Mac with Leopard, download Fluid.app and make yourself an SSB for Gmail. Turn on the "Title Tweaks" option in the google labs part of gmail.

Download iNik's Omnifocus URI Handler app/script

Then save the "Send to OF" bookmarklet as a link on the bookmark bar in your Fluid SSB.

Now, when you have a message open in gmail, if you click the Send to OF bookmarklet, it will create an event in your in book with the subject of the message as the name of the event and a url in the notes field that will take you directly back to that message.

Net result: The SSB gives gmail that behaves more like a stand alone app, and it interconnects with OF.

Or if you don't need the SSB, or you are using Tiger, just do the steps above with the URI Handler Script and bookmarklet in you regular browser.