DeeEmm
One of the best ways is to get people to integrate a warning on their site that display only to IE6 users warning them to upgrade - I already have a mod for D6 for this, and the nice guys here at Boonex have thoughtfully included something similar in D7 - perhaps this should be updated to include IE7 too?
 
 
Below is the legacy version of the Boonex site, maintained for Dolphin.Pro 7.x support.
The new Dolphin solution is powered by UNA Community Management System.
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