Welcome to the 21stC
For a while now I've been looking for a cheap computer to record my commutes. I don't use one on my Mountain bikes so didn't need fancy fittings or dual wheel sizes. I want to keep a track of only basic stats, but the drop bars already have two light brackets so it has to fit out of the way on the stem.
Welcome into my life the SpeedMaster 5000, costing all of £8 from CRC.
I can fit it to the stem and just leave it there, ticking off the (S)miles.