Mr
Rivets The c330 and many others come loaded with many thousands of points of interest such as lodging, restaurants and fuel so you may not need to load anything yourself.
If you have PC mapping software like DeLorme's you can mark a location (click plus you might want to type in a name). About three more clicks outputs a Lat,Long,Name TXT file. Download and use my TXT2CSV conversion software which requires typing in the name of the file created above. Plug the GPS into your PC with the supplied USB cable which supplies power and carries data. Turn on the GPS. Start the POILOADER program, it will find the GPS. Point POILOADER at the folder which contains CSV file you created with my software. All the CSV files in that folder will be uploaded in a instant. You are done. I think this totals less than ten clicks and a very little typing.
Go to
http://users.erols.com/rcarpen to download TXT2CSV.EXE The TXT file name must be eight or fewer character before the periodso you may have to change the one created by DeLorme.
There is a way to mark and save points of interest using just the GPS, but I use the above method.
There is a very good Web site that compares many GPS receivers. Unfortunately it contains adverts so you'll have to send me a PM if you want the URL.