OpenStreetMap (OSM, website) is an Internet-based project aimed at mapping the world using a "wiki"-like method. Users at their website can overlay photos or GPS tracks using web-based software and map. This information can then be saved for use around the world. Much of the current information for the US was imported from U.S. Census Bureau TIGER data... which is generally what commercial mappers initially rely on.
Chico has a number of OSM users and editors. Many things that do not appear on Google Maps, for instance, do appear on OSM. For example, Google Maps as of August 27th, 2009, does not reflect the three new Roundabouts/Traffic Circles on Manzanita Avenue! That could cause quite a surprise to drivers. However, if you were to use OSM, they exist! Another interesting difference between Google Maps and OSM is that, Google, for whatever reason, still has train tracks for the Sacramento Northern Railway following Park Avenue up through the Esplanade! An editor at OSM, however, removed it and replace the appropriate portions of those tracks with bike paths. Way more useful!
Additionally, hiking trails and cycling trails around Chico can be found at the OpenStreetMap project. In fact, two OSM editors have been working on adding trails to Upper and Lower Bidwell Park using Global Positioning System (GPS) tracks.
OSM can also show building outlines, which is particularly useful when it comes to finding your classes at Chico State.
The best part is that OSM uses an open format that anybody can use. For example, software exists that allows OSM data to be used on many Garmin GPSs (Groundtruth makes it a cakewalk). The most recent data for use on GPSs will even route you to a destination. Furthermore, the data can also be exported for use in Geographical Information Systems (GIS) or simply saved to a number of image formats for easy viewing or printing.
Thus with OSM, Chico can be mapped using the latest air photos, GPS tracks, and general knowledge of streets, paths, stores, and more. In the near future Wikispot may use OpenStreetMaps instead of Google Maps. View and/or edit Chico at OSM. You don't need any expensive technology such as a GPS (but if you have one, all the better), just some knowledge of Chico. Whether you trace over lines based on an air photo, go out with your notebook and pen, or organize your friends for a weekend mapping party, anyone can contribute to the map. See their FAQ for more information.