Rated 5 out of 5 stars
Open the .xpi with Winzip (or another zip utility), open the .rdf file with Notepad. Find the Max Version number and change it to 3.0. Save the .rdf file back. Make sure it's updated in Winzip. Use the File->open to install. Works great in 3.0. (Note, use the above instructions at your own risk on other extensions - I know works great on this one.)This review is for a previous version of the add-on (1.2.200803).