We've been working with the nordic ski community to address a long-term need of an affordable, simple race (and training) timer capable to recording splits and calculating relative racer position live during events (or training sessions). The result is an application for the iPhone called RaceSplitter.
RaceSplitter - Race timer for the iPhone and iPod Touch
The app has been really well received by our beta testers, and is now commercially available. I just wanted to make a short post announcing RaceSplitter. I'd be happy to answer any questions you may have about the produce, either privately or here in the forum.