If you are into aeronautical monitoring, especially on the HF bands monitoring MWARA comms, then you will want to checkout the free digital chart downloads on the FAA website at http://aeronav.faa.gov/index.asp?xml=aeronav/applications.
You can get Caribbean, Atlantic, and Pacific Enroute charts in PDF format that will show reporting waypoints you can use to pinpoint the flights you are monitoring if you are into flight following.
Here is a list of goodies you will find on this page for download:
Sectional Raster Charts
VFR Terminal Area Raster Charts
World Raster Charts
Helicopter Route Raster Charts
IFR Enroute Charts
Caribbean, Atlantic & Pacific Enroute Charts
Gulf of Mexico Charts
Digital Aeronautical Chart Supplement
Digital Obstacle File
Navaid Digital Data File
Geodetic Calculations (Compsys 21)
Aeronautical Chart User's Guide
VFR Chart Update Bulletins
Digital Aeronautical Chart Supplement Change Notice
This is some pretty good stuff and the best part is this is a free service. have fun and good hunting.