GM announced today that it will be making its OnStar Turn-by-Turn navigation system standard on a number of 2007 models and that the first year of service will be free. Owners of vehicles already equipped with OnStar can also have the service activated through an optional $100 OnStar package upgrade within their first year of use. Turn-by-Turn is considered an "off-board" GPS navigation system because the heavy lifting is done by OnStar advisors and a centrally-managed remote database. Users just push the blue OnStar button, tell a real person where they want to go and voice-guided directions will be pumped through the vehicle's stereo system. It features automatic route corrections and the ability to pick up where it left off after an unscheduled Mountain Dew-induced bathroom break. The system's centrally managed database also continually updates itself with points of interest, so when the main vain needs to be drained again you can call up an OnStar advisor and ask how many miles until the next McDonalds bathroom. Hold on to your wallets, though. After the first initial year of free service, Turn-by-turn navigation will cost OnStar users an additional $299 per year. Yowsers. A couple years of that would easily pay for a nice third third-party navigation system. But then who would you talk to?