The Google Maps API can be used to overlay information on a map. Many sites have created interactive maps that present all sorts of useful information. I found a few maps that can be very helpful when preparing for a bike ride in Durham.
The first site, Durham Bike Racks, features an interactive map of locations to park your bike in Durham.

Above: map showing where to park your bike in Durham (with photos!).
There were a lot of bike racks listed, and it looks pretty comprehensive. You can click on the icon for each bike rack to view a photo of the bike rack and read more information about parking your bike. It’s a great tool to use when planning a bike trip or a commute in Durham. You can help by browsing the map and adding bike racks that are not listed.
The second link is a map of bike routes in Durham, built using Wayfaring. Wayfaring allows users to create and share interactive maps, and has an interface that is much nicer than other such sites I have used. It is interactive and shows 20 or so intersecting routes, trails, paths, and bike lanes. It is a nice map, and gave me some ideas for trails I can check out.

Above: map of the many intersecting bike routes and trails.
Another map site is Bikely. This site is not as popular as Wayfaring, but it does pretty much the same thing, with one main difference. It is tailored to bike routes, and because of this it has additional features, such as graphing of the route’s elevation. It allows users to search for rides from their area, comment on routes, and export the routes for use with other programs. This site is definitely worth visiting.

Above: a useful feature of Bikely is the elevation graphs it generates (x=distance, y=elevation). This is from the Halloween 100 ride.
On an unrelated note, I am hoping to get out and ride this weekend (Duke Forest maybe?), if the weather holds up (which it’s looking like it will). So either way expect an update next week.