Microsoft offers tabbed browsing--in IE 6 - a new function of the MSN toolbar
This new add on to the MSN toolbar appears to be a last ditch effort by Microsoft to keep people from abandoning IE6 until the new IE7 comes out. If tabbed browsing is all you really want, I'd actually recommend that you use FireFox. For IE based browsing, try Avant Browser, SlimBrowser, or Maxthon before you resort to the toolbar. I don't know what the privacy concerns are for using this toolbar, but I'm not sure I can trust Microsoft to keep their prying eyes out of my surfing.
Warning: Some of the tabbed browsers above use IE for bringing in web pages, alway keep your Windows updated and check your browser security at one of the test sites. Even FireFox has the occasional security hole in it so keep it up to date also.
Quote from the website -
NEW! Browse smarter with tabs - Switch between Web sites within the same Internet Explorer window
NEW! Find anything - Search the Web any time, anywhere, and easily locate documents, e-mail messages, and more on your PC
Shop faster - Fill out online forms with one click
Access MSN services - Get one-click access to Hotmail, MSN Messenger, and MSN Spaces