Google Geography: Maps from GPS Data
You can import data files into Google Maps. One of the easiest ways is to grab the file right from your GPS unit using the GPSies conversion tool. Once you have created a .KML file, click the import button. Click Choose File in the window that pops up. Once you have the correct file, just click upload and the path will be loaded into your map!!
Here is a sample from two recent bike rides. You might have to scroll a bit to see both rides. These were both tracks, in which the GPS automatically records specific locations in set time intervals. You can also mark points as you hike or research and import those into your map. You could then come back and add descriptions, pictures and other data to place marks at each point. Think of the native plant data you could generate by exact latitude and longitude... or perhaps animal sightings, urban sightings, etc.