Yes, common-mode choke or a balanced isolation transformer, appropriately sized for the load. A number of the "line conditioner" manufacturers like APC and Belkin PureAV employ common mode chokes in their products. I have been using balanced isolation transformers with great success over the past 8+ years.
http://i994.photobucket.com/albums/af67/mr_classe/General/belkin_zps16c121f8.jpg
http://i994.photobucket.com/albums/af67/mr_classe/General/APC_zpse05a8f0b.jpg
http://i994.photobucket.com/albums/af67/mr_classe/General/furman_pf15i.jpg
http://i994.photobucket.com/albums/af67/mr_classe/General/belkin_zps16c121f8.jpg
http://i994.photobucket.com/albums/af67/mr_classe/General/APC_zpse05a8f0b.jpg
http://i994.photobucket.com/albums/af67/mr_classe/General/furman_pf15i.jpg