OpenStreetMap

A Wiki World Map
My Garmin GPS Maps
Born Slippy

OpenStreetMap is a wiki world map. I'm as keen on it as I am on Wikipedia, which is to say that it makes me say "squee!" in a giddy fashion. People can do whatever they want with the data, like custom cycle maps, or Garmin maps for your GPS, or cycle maps on your Garmin. You can do all this without any royalties or licence fees.

When you make edits, they appear within a week, making the map potentially the freshest world streetmap by far. That gives the community vibe of practical participation - wikisquee - and means that a handful of individuals can have a mapping party and get their area lovely (whether that's Devon, Faro or Gaza - there are UN staffers out there with GPS and bicycle mapping suburbs so that aid can be distributed).

My Garmin GPS Maps

I like contours on my maps, so I've combined the OpenStreetMap tiles with the Scottish Mountaineering Club's topological tiles to give a Garmin GPS map of the UK and Ireland with both.

The freshest maps are available here: http://www.ravenfamily.org/andyg/maps

There may be two files for a date. The one with "BRIGHT" at the end of the name is built using a very colourful style sheet. It's a love/hate thing; if in doubt, get both.

The OSM map tiles and stylesheet are compiled by OSM user ComputerTeddy.

Born Slippy

This is the "slippy map", the OSM main web map:

You can drag it around, zoom, and generally have fun.

Data overlays are supported through OpenLayers. Here are directions on how to do it for simple static data and here's how to do larger dynamic POI.