We’ve put a fair number of maps on websites over the past few years: while the most common reason is to indicate the physical location(s) of the company whose website it is; sometimes the maps will have a more functional purpose, complementing text-based information with visuals.
Below are a few examples of maps we’ve added to websites.  The first three examples are maps that update themselves automatically, in fact the administrators don’t have to do anything with these maps, they generate themselves, positioning and displaying map markers based on database information, whether it is tax sale records, location records, or event records.  All of the sites listed below were developed in they TYPO3 content management system.
Ontario Tax Sales: Upcoming Tax Sales Map
OntarioTaxSales.ca works with municipalities in Ontario to list all of the upcoming tax sales. While text-based listings are available, a map is also provided that shows a thumbtack in every municipality that has properties coming up for sale. Hovering over a thumbtack displays a summary of whats going on in that municipality, and clicking on it takes one to the listings pages with full details.  The thumbtacks are placed according to the information in the database, and so are always up to date with the most recent upcoming tax sales in the system.

In the coming weeks this site will also be adding a map for Tax Sale Results.  You can visit the map at http://www.ontariotaxsales.ca/upcoming-ontario-tax-sales/search-by-map/
My Auto Cafe:  Businesses Location & Related Businesses
MyAutoCafe.com is a site that provides a database of auto-related businesses in Canada.  One can use it to find mechanics, paint shops, or other auto-related businesses near one’s postal code or city.
Each business is presented with a location map, and below the map are a series of check boxes for different categories, allowing one to also display other business-types on the map.  Handy if for instance you might want a mechanic, tire shop, and towing company.

Visit the site at www.myautocafe.com.
Galeria Arte Hispano:  Event Locations
GaleriaArteHispano.com is a site that provides an online gallery for Hispanic Visual Artists.  Also listed are subject-relevant news and events. Many of the events provide location maps, so that people attending can look up the location and get directions as well.  This is an integration of the Google Maps interface (as is the auto-cafe site above).

Visit the site at www.galeriaartehispano.com.
Wellspring Location Map
Wellspring is a network of cancer support centres with locations across Canada.  Locations are indicated on the map by a green bullet, which if one hovers their mouse over will display the location name, and if clicked will take one to that page of the website.
To be able to display the full country, and to also clearly indicate the numerous locations in Southern Ontario, a zoom-able section was created and indicated around this area.  As ones mouse hovers over this area, the entire section expands.

Visit the site at wellspring.ca/locations.html.
The first and last example above are maps that are created with Flash technology, the first one dynamically updating the flash from the data that is in the tax sales database.  The middle two examples are both integrations of the Google mapping interface.  Of course, we’ve also done sites that have static pictures of maps placed on them as well.