And Arial is the best font for email signatures - while Microsoft Outlook recommends Calibre, people who are not on vista or Office 2007 may not have the Calibre font on their machines:
Tris Hussey has more advice for email signatures that work at pimpyourwork.com/
1. Spell out websites. Don’t count on the HTML signature to work all the time. Instead of making a hyperlink like “My website” use http://www.onebyonemedia.com. This also lets people copy and paste into a browser or contact card.
2. Forget the little quotes. While you might think your quote is pithy or wise or funny, it might offend someone or just be confusing.
3. Stick with black text and simple fonts. Arial is on every machine in the world and it was designed to be easily readable on screen.