If you’ve got several Gmail accounts and are frequently having to juggle signatures for each of them, worth downloading is Blank Canvas’ Gmail Signatures. This experimental Firefox extension will drop in one of four custom HTML signatures based on whichever account you’re sending the message from.

See Also: How to Add email Signature in GMAIL
This extension for Firefox automatically inserts HTML signatures into your Gmail messages based on which address you are sending from. Works for Compose Message and Reply/Forward.
Features:
- Works for Compose Mail, Reply, and Forward
- Support for single or multiple email addresses
- Create a different signature for each email address you use in your Gmail account
- Supports up to four signatures per address
- Real-time signature preview while editing signature HTML
- Signature automatically inserted into message above (or optionally below) quoted text
- Support for special characters
- Easy setup and configuration interface






Thanks for the article. Just for the record, the add-on’s home page is http://blankcanvasweb.com/pages/detail/id_9/n_gmail_signatures/ where you can get updates and support.