Updated June 27, 2018
OpenStreetMap is similar to other map services online. It has a map you drag around on screen, it shows roads and points of interest, and it has a search. If you understand open source software you know what is about to be said. Unlike those other services the data and software is open and usable under permissable licenses which is rare.
Another difference between OpenStreetMap and other maps is OSM maps what is on the ground while other services use legislative boundaries. For example, the City of Gillette Maps will show property boundaries even when it splits a house in half or what zone a piece of land is. OSM in Gillette would show where the residential area ends on the ground and would show the duplex as one building with multiple addresses inside.
If you don't know anything about programming, databases, research, or surveying what can you do with it? OSM can be used in online and offline car, bike, and hiking navigation. There are weather and census data overlays, interactive 3D interfaces, and of course ways to search and browse for businesses. Pokemon Go players might know OSM is used for their maps and determines spawn types.
I previously ran a link directory for Gillette which was replaced by this page. Using OpenStreetMap has several advantages over a link directory. It verifies everything is actually in Gillette and it can show places that don't have a website. Editing OSM puts that info into a global map instead of a city only directory.
If OpenStreetMap is so great what is the catch? I have read entire essays on that topic, though here are just a few issues. OSM lacks many addresses and other details. In parts of Europe and major American cities the mappers have added an incredible level of detail while rural America might only have roads from TIGER data. The OpenStreetMap interface is mediocre at best and it has a minor issue of everything using British English. What, you've never taken the bloody lift at the aerodrome? Bollocks.
OpenStreetMap has routing, search, and editing. The interface works better for editors instead of users.
OpenStreetBrowser lets you browse by category. I added hundreds of custom categories based on how OSM organizes things. It isn't pretty or perfect, though it mostly works. Try browsing the amenity, leisure, office, and shop categories.
Geofabrik Map Compare shows a realtime comparison of OpenStreetMap and Google Maps. OSM is on the left and Google Maps are on the right. Looks can be deceiving.
City Data has a large Gillette page which includes a map overlay with census data about race, gender, income, employment, age, and housing costs.
Dark Sky Maps overlays temperature, UV, cloud cover, and emoji data on OpenStreetMap.
F4 3D Map shows buildings in 3D using several OpenStreetMap tags for building height, roof shape, and colors.
Every map has its problems and these tools help OpenStreetMap editors fix them. No matter how many problems are solved it seems the issues in Gillette area are infinite.
Geofabrik OSM Inspector reports a few types of errors and some information especially with addresses.
Keep Right not only reports several types of mistakes it also checks URLs in website tags.
Osmose reports so many problems it requires zooming in to see them all. Many of these have been fixed since this screenshot.
Just because I cover OpenStreetMap extensively doesn't mean there aren't other great map services out there. Here are just a few of those maps.
The City of Gillette maps have all the addresses, but not the businesses or the ability to navigate using it. There are overlays for legislative boundaries and even art installations.
Exploring Campbell County History is a map from the Campbell County government combined with information from the Campbell County Rockpile Museum. Knowing about historical events is one thing and seeing a map where they took place is another.
Dark Site Finder is a light pollution map. Use it to find good stargazing areas.
GeoHack isn't a map, but a huge resource linking to many other services. Most of the other maps I link to here are not on GeoHack.
Google Maps are a mix of data from several sources including OpenStreetMap. It has a slick interface and is linked to Google's image search, street view, and other services. Despite the spam, old data, bad or missing businesses, and other issues it is still a great map.
Tornado History Project shows the paths, strengths, and damage caused by tornadoes from 1950-present using Google Maps.