Google Maps Terrain Downloader is a tool that help you to get small tile terrain map images from Google Maps. All downloaded small terrain images are saved on the disk. You can view downloaded maps by Terrain Map Viewer Or you can combine them into a big BMP map.
Note: The downloaded images are only for your personal purpose, non-commercial use.

It is very easy to use. Click here to see how to use it. And here is an downloaded images example under zoom 8.

It is a shareware, for trial version, you can not download high precision images (For trial version, the min zoom level is 8; for registered version, the max zoom level is 0). It is cost you only 29.95$!