GMail has a nice keyboard accelerated web interface making it competitive to desktop mail clients as Thunderbird and even Mutt. One reason I stayed with Mutt for a long time was the ability to integrate with Vim. I switched to GMail’s web interface for other reasons, but nevertheless it was delightful to discover ItsAllText; a Firefox add-on that allows you to edit any textarea in an external editor.

You can make Vim automatically activate the mail file type plugin when edit a GMail message by adding the following to ~/.vimrc:

autocmd BufRead* setlocal ft=mail

Further customization go in ~/.vim/ftplugin/mail.vim:

setl textwidth=68
call IMAP("sig1","<++>Med venlig hilsen,nMads...","mail")
call IMAP("sig2","<++>Regards,nMads...","mail")

Wrapping your text makes your mail appear more readable and professional, as the line width does not depend on the width of the receivers window. Remember that GMail automatically wraps text at the 72th column, so be sure that textwidth is lesser than that if you set it. The IMAP lines uses imaps to provide an easy way to handle multiple signatures. The <++> thing indicates where to put the cursor; see the comments in imaps.vim for further info.

Likewise, you can set up Vim to use special syntax highlighting on wiki pages that are edited as plain text. This is great when working with for instance twiki pages on Trac.