James T. just sent me an email with a most excellent Windows 7 tip: You can use the new taskbar to perform drag and drop file associations!
To make this work, simply drag a document file (like a Word Doc or JPEG) onto the taskbar button for the application with which you’d like to associate that type. Voila!
I haven’t tested this extensively yet, but it does appear to work. Good stuff! And nice catch, James.