maps.google.com

Latitude - Longitude - 
Find location: 41.857288,-73.917217
  or +38° 34' 24.00", -109° 32' 57.00"

Find coordinates:
1. Lat Long will be in the ll= parameter in the URL results of a search for an address.

2. go to https://maps.google.com/maps?showlabs=1

Enable "LatLng Tooltip" and "LatLng Marker".

To drop a LatLng marker, right-click and select "Drop LatLng Marker" in the contextial
menu (then you can select and copy/paste the Latitude and Longitude from the marker).

This is much nicer and easier than looking for the Latitude and Longitude in the URL.