News.com reports that the California Public Utilities Commission has approved the testing of broadband over power line technology (BPL), opening up a third option for high-speed internet service. The BPL technology uses existing power lines to carry broadband signals into the home. Advocates hope that this technology will allow electric companies to become a viable alternative to cable and telephone providers. The technology has been hampered by technical limitations, notably interference from emergency and amateur radios. Despite this, several utilities across the nation are investigating this technology, while big companies such as Google, IBM, and EarthLink are investing in it…