MapMyRide.com. I haven't played with it much yet, but my impression so far is that it's pretty cool. You can set a specific starting point in your profile so that loads that location when you log in, and you can add specific markers for water, bathroom, etc along the route. It's a bit sluggish and definitely easier to work with in full-screen mode, but could be a nifty alternative to RouteSlip and Bikely.
