GUI tools:

• Map Creation Tool, a web interface that allows you to select a region and generate a .map definition file. See the forum thread for more details.
• UPDATED: gMapMaker v0.7.3.8, Map Tile Downloader for Windows. Read the installation instructions here. This version supports multiple simultaneous downloads, multiple tiles per file and Google, MSN, Yahoo, OpenStreetMap as map sources. Alternate download: gMapMaker (MSI installer).
• gMapMaker source code, for developers who want to extend the application. It is available under the GNU General Public License.

Perl (command-line) tools:

• Map Tile Cacher, v1.39. This script downloads and stores map tiles for an area for a given zoom level and map type.
• MapTileFE, v1.23 with Tokyo and HongKong map definitions. This is a batch downloader that invokes MapTileCacher several times to download multiple zoom levels, see the forum for more details. Works on Linux, Mac and Windows!
• KML to .map converter. This script generates map definitions based on LineString elements in KML files.
• Re-hash script, v1.01. This script can re-arrange the downloaded files into more or less folders by changing the "hash size" setting (useful for performance tuning).
• Migration script from MapTileCacher <v1.10. Use it to upgrade an MGMapsCacheV1 folder to MGMapsCache (v2).

Note: in order to run these Perl tools in Windows you need to install Cygwin or ActivePerl and wget.