What are the missing accessories for you cyclists? I am a technology guy and I would like to ask you cyclists, what are the missing accessories with your bike that you want us to do for you? In a project at school, I am asked to use the following sensors: gyroscope, accelerometer, microphone, barometer, magnetometer, compass or the various devices: cameras, geo-location, RFID, wireless transmission, ultra low power devices to make a useful accessory for you guys bikers. Can you guys tell us what are the obligatory accessories you need for your bikes?
H. P. - welcome to bikes.se and thanks for asking.

One feature I have not seen on bike computers or iphone apps is a simple tool that tells you how much money you have saved through cycling.

To drive a mile takes a certain amount of petrol/diesel and that depends on many factors. These factors can be approximated in a multitude of ways, so you can start off with a simple miles to the gallon factor then extend the model to take into account the start/stops, the speed, the weather (A.C. in summer), car engine size and so on. Some algorithm optimisations will not be that big a deal, others will be important to accuracy.

The car data is also important. As well as efficiency there is also the depreciation, insurance and other costs. You could have ballpark figures for 'large saloon', 'small hatch', 'fullsize SUV' and so on. Also there is the difference in saving depending on whether or not the car is given up.

Fuel prices change by the day and by region. Applying accurate prices to the data is another factor that can be approximated or accurately modelled. For instance, if we were to have another war or gulf hurricane then prices could go off the chart, so you can either model 'today's prices' or make the data tied into the price by date. Clearly this data needs to come from somewhere, either it is manually keyed in or else it gets it 'from the cloud' somehow.

Ideally the app just needs to know what car you drive or what car you sold. After that it should be able to work out the rest.

To what ends?

You could have this data used by employers wishing to remunerate employees for cycling to work, you could also have parents that 'run a taxi service' make pocket money dependent on whether the kids cycle to school or not.

As a spin off you could also measure Kg of CO2 saved by cycling.

If the challenge of the above appeals to you then you could make an iphone/android app to do the above and sell it on the app marketplace, hopefully to make your efforts financially worth your investment in time.

Hope that helps!