Mapping Extensions for Firefox has a great post on mapping extensions for Firefox.

Here are a few highlights:

  • Mini Map Sidebar: The Minimap Addon gives you a suite of in-built maps and mapping tools for your web browser. Create and save a sidebar map using the addresses or address links you find on web pages (highlight then drag and drop), or by manually adding locations. View traffic Info, drag and drop kml files, local search, Google, Yahoo and Live Local directions, view in google earth, tagzania, platial, geourl and many more. Address/Location points are stored locally for later use.
  • Extension: This extension makes it easy to get tracking information for a package and display the tracking progress on Google Maps. It works with UPS, USPS, FedEx, and DHL.
  • Locator: Locates selected address on Google map: simply select the address, right click with mouse, 'Locate on Google Map' and your place will be located on the map.
  • GDirections: Finds directions on Google and Yahoo Maps based on your selected text and one of various home addresses.