San Diego-based Slacker, which operates an online personalized Internet radio and associated hardware players, told its users today that it has rolled out a new, lower price offering. The firm said its new "Radio Plus" service will allow for ad-free, unlimited song skipping for $3.99 a month based on an annual subscription. The new service is a significant cut from $7.50 per month. Slacker runs a personal Internet radio service which automatically downloads playlists to a Wi-Fi enabled hardware device, or which can be listened to via PC. The firm is venture backed by Austin Ventures, Centennial Ventures, Mission Ventures, and Sevin Rosen Funds.