I have a Garmin Forerunner 305 (which is a GPS running/biking workout helper) and a Canon 870IS (pocket digital camera). Since each device records the date/time with its information, you can later combine the latitude/longitude from the GPS with the photos from the camera to be able to see pretty exactly where your photos were taken (this is called "geotagging" your photos) and to create something like this:
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In this post, I'll go through the various steps necessary to create that result using my GPS logger and digital photo set-up but many of them are transferrable to other loggers and set ups (though at $169, last I checked, the 305 is a steal). I use Picasa, Google Maps and Google Earth because I think they are good products but you should know that I may not be unbiased because I also work at Google. Other photo managers and hosting services can be used. From the looks of it, Flickr does this very well too.
If you haven't already, you'll need to install the Garmin Forerunner 305 drivers and software (these links are for Windows). Then open up the Garmin Training Center software (ug, relatively horrible and proprietary) and download your GPS log from the device. Find the part of your "history" from when you took the pictures and note the date/time from the very first entry (you'll need it later). You should then be able to right-click on your log and "Export" it. Unfortunately you can only export in the little-supported Garmin format, so choose a place where you'll be able to find it and export as .tcx.
There are a number of ways to convert from TCX to GPX (a much more commonly supported format). I used the online converter from gpsvisualizer. You could also download a perl script to do it locally. In either case, you need to save the resulting GPX file for the next step.