GPS's for bicycles are emerging, and they offer a lot. No more measuring the radius of your wheel ... just add batteries and go. Some include heart rate montiors (with the constrictive chest strap).
Though bike-focused GPS units do well as bike computers, in time they will likely do more. Imagine hitting a website and downloading a local route or waypoints from a friend or stranger to the unit. Then make your way to the starting point and hit GO to start the race. Nevermind that your competitor may have done his/her race weeks or years earlier ... you're going head to head on the screen! And you can upload the results for bragging rights.
In a race with waves, downloading the progress of others in real time (which goes beyond a GPS's capability now) would make it more of a head-to-head race.
What if data about poorly surveyed areas was aggregated to give a sense of the altitude of land masses?
Or if non-road routes were aggregates for map makers, who could analyze the data to locate popular trails that may have never been recorded (or intended by any authority!). Or imagine you were in an unfamiliar area and you could download non-road paths that were popular -- ie. to the GPS unit a field is a field, but if 30 people have ridden a particular route through that field, it might suggest the same to you.
They would likely also serve as Black Boxes in the case of an accident -- something that cyclists prone to breaking traffic laws should be mindful of.
