GoForSmoke:
Arduino is a development board. You can program AVR chips to put in end-products.
You mean, dus take the chip from the board qnd put it on some PCB? That's what I'm planning to do in the end, indeed.
The anemometer sounds fun! Would need some calculations to leave the bike speed out of the wind speed, but that must be not that big of a problem.
I agree with stoopkid on the magnet sensor. Two updates a second (well, more most of the time, since 10mph isn't that fast), is good for me. Maybe in the end I'll want to update it, but for now it's ok.
Stoopkid, I will start with the speed only, yes. I havbe a hometrainer which is great for testing indoor, so I can work out the speed, cadance and heart rate easily.
Good. For now I'll just order some reed sensors and give it a first go.
Thanks guys, I'll keep you updated!