I use Microsoft Streets and Trips, but would like to integrate POIs giving in depth travel information on historical sites or other places of interest as we travel. Is there an add on or another software package I can use?

You can add a link in the pushpin address information. The link can reference a web page and take you there, or reference an internal file (containing whatever you like) on your computer and open it. There's no need to switch software. Read this: http://www.laptopgpsworld.com/145-pushpin-links-files-folders

Thanks t1dunn, had a look at the link, but was looking for a method, or a piece of software, that cross referenced your location from your GPS position, and did a lookup of information contained in the software, and gave you a heads up of what was coming down the road, or was within a certain radius of your position.

There is an add-on piece of freeware that is reviewed in this forum that scans out in front of you and alerts you to upcoming POIs. I'll try to find it and re-post.