We just released details on the new MBTiles file format designed for portability of thousands, hundreds of thousands, or even millions of standard map tile images in a single file. This format makes it easier to transfer map tiles to mobile applications like Maps on a Stick and our upcoming iPad app for MapBox, and it makes it possible to use very detailed map tiles while offline.
In addition to storing tiles, MBTiles files also contain metadata about the tile images, including tile set name, description, zoom levels, attribution, and more. Technical details about MBTiles are on the MapBox website. There, you can find out how the format is made, our reasoning behind it, and the various benefits of using it.
We've also released a command-line import tool to convert any map tiles that you might have available to the MBTiles format. This tool is available on the MapBox website. Currently it is only available in binary form for the Mac, but we're working on a cross-platform, open source version that will run on any UNIX variant.
We'd love to have your feedback on both the current state as well as the future of the MBTiles format. MBTiles is the best way we've come up with to easily transport millions of map tile images and quickly make them available for offline use, greatly expanding the power of mapping for a variety of uses.