favicon.ico

[Kurt Wall]

Many Web sites (www.mozilla.org and slashdot come to mind) have a little
icon that appears at the beginning of the URL in the address bar of
Web browsers and on tabs and in (some) bookmark pages. Several
questions:

1) Is this icon a Windows .ico format file or what? 
2) What are the requirements, such as size and number of colors, 
   for said file?
3) What is the magic CSS or HTML incantation that makes it appear
   in Web browsers?

Thanks,

Kurt
-- 
f u cn rd ths, u cn gt a gd jb n cmptr prgrmmng.