Add Multiple, Address-Specific HTML Signatures to New Gmail
Firefox with Greasemonkey: If the upgrade to the new version of
Gmail made you leave your HTML signatures behind, you're in
luck. The Gmail 2.0 Multiple HTML Signatures Greasemonkey user
script (wow, that's a mouthful) can associate rich text
signatures to individual addresses in Gmail, and include them
above the quoted text in replies. Unfortunately the user script
requires that you edit its source to set up your sigs: once it's
installed, in Greasemonkey's Manage Scripts dialog, hit the Edit
button. In the area labeled "Setup/Configuration," enter your
email address(es), and your signature markup. Use the pre-filled
examples to get started. Because this script requires hand
source-editing, it'll take some work to get it implemented in
Better Gmail 2, but it's on the roadmap. The Multiple HTML
Signatures user script is a free download that works with
Greasemonkey in Firefox.