My Fave: WiseStamp
WiseStamp lets you add a personalized signature on any webmail service such as Gmail, Yahoo, AOL mail, and Hotmail.
- Customize your Email signature
Design style, Font, Size, Color, images etc…
- Add Email Apps with updating dynamic content
Automatically Share your latest blog posts, Tweet , Facebook status or Ebay item, etc.
- Easily include your social services& Profiles
Facebook, Twitter, del.icio.us, IM Services, LinkedIn, and many more..
- Use multiple signatures Create business & personal signatures to insert in your emails.
- Add your personal feeds (rss)
- Add your logo or image to your signature
Make sure to check out WiseStamp Email Apps gallery
Find out more on WiseStamp.com