I don't use IE6, and haven't for a long time, so this is an assumption based on trying to get into the mindset of someone who 1) is still using IE6 and 2) has control over the update (ie, ignoring those in large corporates who can't update themselves). If I'm using IE6, do I even know what a "browser" is? Let along an "outdated one"? And what, exactly, are the five colourful round things on the bottom of the page? Ah…
The Microsoft banner is horrendous too. If you must (because your functionality doesn't work on IE6), give them a text link to the Microsoft upgrade page with a "You need to update your Internet Explorer for this site to work correctly. You can do this by going to the Microsoft free download page _here_. You can also find out more about the latest version by going to Microsoft.com and searching for Internet Explorer".
Other options (probably via browserchoice.eu) should be secondary. And I say this despite IE8 being a horrible browser I wouldn't use voluntarily.