Registered users can save their favorite maps for later viewing. Each map's info page has add/remove buttons, and all of your maps are available via the 'Favorites' link in your user bar. Google Earth exports also available.
There are now links for Google Earth exports on a map's Info page. Google Earth is absolutely amazing, check it out! Exports will be added shortly for groups of maps. Update: GE exports are available for all maps, categories, states, countries, and more!
Congrats to the map submissions contest winners! Tons of great maps (non-US mainly) have been submitted lately, and I would love to thank everyone who's participated. Look for another contest in a few weeks!