Learn more about Geocaching at:
http://www.geocaching.com (need to log in)
Or, just for an overview, go to http://www.geocaching.com/faq/
Latitude and Longitude
Get a mini-map and coordinate converter here:
How Far Between Latitude and Longitude?
Roughly speaking, it's .019 miles, or about 100 feet, between seconds of latitude, and .013 miles, or about 68 feet between seconds of longitude.
A great place to calculate distance is at http://www.wcrl.ars.usda.gov/cec/java/lat-long.htm (remember a mile is 5280 feet).
Looking Up Addresses
You can enter a street address at http://geocoder.us but the latitude and longitude results come back in the decimal format, not minutes and seconds.
To covert it, simply take the decimal and multiply by 60, then move the decimal in two places.
i.e. 47.207354 ... .207354 x 60 = 12.441240... so it's
If you're unsure, use the converter at the top of the page.
Combining with HAM Radio
With a GPS unit connected to a special ham radio, you can actually see the travels and locations of various ham radio operators anywhere in the world. Visit the Northwest Automatic Positioning System at http://www.nwaprs.net/ -- give it a few minutes to show everybody. Use the "findu" feature to enter a callsign for more detail.