Excellent Rated 5 out of 5 stars

I absolutely love this add-on, and they do a wonderful job of compiling some o the best Gmail scripts out there. Note that the Gmail HTML Signatures option has been replaced by a more stable stand-alone add-on:

http://blankcanvasweb.com/pages/detail/id_9/n_gmail_signatures/

This review is for a previous version of the add-on (0.5).