Well, after being asked by my cousin "By the way, does Firefox RC4 not have a "Send link to this page" function? command + shift + I?", I was on the search. Better yet... I should say, I entered the rabbit hole.... but to save you the same Google search and "not exactly what I'm looking for" link clicking, refreshing and back button wearing out activities, I'll just tell you how it's done.
My configuration for this change (this may not work on any other versions, as this is the only setup I have tested):
Mac mini - Intel - Mac OS X 10.6.6 and Firefox - 3.6.15
2. You will get a series of pop-ups and security warnings from Firefox
2a. Click "Allow"
2b. Click "Install now"
2c. Click "Restart Firefox"
3. From the Firefox menu select Tools > Keyconfig
4. Add the context for your new shorcut key, in the following steps...
4a. Click "Add a new key"
4b. Name your key "Send mail"
4c. Paste the following context into the "CODE" area: MailIntegration.sendLinkForWindow(window.content);
4d. Click "okay"
4e. You will then see a field under the name column, with "Send mail" highlighted. Below that, there is a field you can enter your new series of key strokes to activate your new shortcut. I used "Shift - command (flower/Apple) - I (capital i)", since it was used by Safari and that's what I am used to using to send a link. You can, of course, create your own key! Remember, you are actually pressing the key combination you want to use - not typing it in
4f. Click "Apply", then "close"
5. Restart Firefox and try your new shortcut key!
Please feel free to ask me any questions and or report problems, thanks!