Here is a great overlay for Streets and Trips 2010:

http://www.discoveryowners.com/MS2010.htm

It will show you where lots and lots of places are that we are all very interested in.  Examples include Flying J, rest areas, low clearances, Passport America parks and much more.  

I downloaded it from the above Discovery owners site, unzipped it and then opened it with the "Open File" command on Streets and Trips, just the way I would open a saved map (or route) file.  Once it opens, you will see a list of all of the pushpin sets included with it on a list on the left side of the screen.  You can then right click on any title and then select "show pushpin set" or "hide pushpin set" as you need to to utilize the information.

It comes with the ski areas, Colorado rest areas and Arizona rest areas shown, so the first step would be to hide those three sets then bring up the ones that you want.  

I have not tried it with earlier versions of Streets and Trips and I am not sure that the ability to show and hide is on these earlier versions.  The file would create too much map clutter if you could not hide what you do not need.  Try it if you want and let us all know how it worked.  The overlay should go away when you close Streets and Trips and if you don't like it just don't reopen it next time you start Streets and Trips.

Fun!

Bruce