Not really. There are a couple apps out there like trekbuddy that you can use to store maps with but it doesn't help unless you have all the map data you know you are going to need.
If all you're after is a set of lat-long coordinates, you can just use the Options -> GPS menu, and that will definitely not use data (to be 100% sure, turn assistance off).
If you want anything else, you will have to use data.
But like previously stated, as data is to "download the maps" so you know where you are, you have to have downloaded/installed all the maps manually first.
Unless Garmin comes packaged with the maps, but its not exactly a cheap option.
You download the maps you need at different zoom levels you want using this tool - Map Creation Tool for MGMaps . I had the entire country from zoom levels of I believe 4-10. Then my hometown from 10-16.
And if you need any help, feel free to ask. I know it was a little confusing at first to get it to work so I'm happy to help someone else out. And using Google map tiles didn't work, so I used Microsoft Live.