IE v7 is finally out of Beta test. You can download the new version from the Microsoft site for free.

Biggest change is tabbed browsing: you can have one instance of the browser open several web sites at once and make them available through "tabs" at the top of the screen.

There was a review of the update in the Wall Street Journal (Walter Mossberg' column) a couple of days ago. General opinion was it was a 'catchup' update, but is worth upgrading.