The maps that illustrate each of the cycle rides I post on here show the actual route that I took, as tracked by a GPS receiver. This just sits on my handlebars, and takes a reading of my location every couple of seconds. The magic of GPSvisualizer.com then overlays this onto Google Maps.

Updated for 2010:
At the time of writing, basic GPS units can be bought on eBay for about £60. More useful though is a GPS unit with mapping capabilities, specifically designed for cycling—such as the Garmin Edge 605, shown left (currently approx £280 at Halfords, but it’s sometimes available for less on eBay). These can hold ridiculous amounts of information—mine holds address information (down to house number) for the whole of Europe, and can calculate new routes on the fly, whilst you’re on the road.

It might not be entirely obvious why this is useful, but picture the scene: You’re out cycling in the open countryside, and come to a fork in the road. Which way do you turn? In the Fens, it can often be the case that taking one road will send you on a 5 mile detour around a farm … joining the other road just a few metres along from the original fork. How frustrating is that?

GPS mapping units can also be helpful when planning out a route to take, as you can plot a detailed plan on your PC at home, and then upload the details of every turn to your handheld unit. Many units—such as the Edge—will beep to alert you before junctions, showing you an expanded view of the road ahead. Units designed with cycling in mind often come with a handlebar mount, which will then allow the unit to sit comfortably beside your front light.

It’s a bit of a luxury, but in my case this is one of the best gadgety purchases I’ve made in a while—it has all the standard functions of a normal cycle computer and means that I can take in the views rather than faffing around with paper maps every few minutes!