I'm new to all this so please bear with me . I bought an N800 hoping that I would be able to use Winmapper to obtain maps then transfer them onto the device and view them on Maemo mapper. I now know that Winmapper does not work with Maemo mapper 2.x, as it uses image tiles wheras maemo now uses some sort of database. I had already downloaded an area on winmapper, at level three (detailed) and wanted to view it on maemo, but I couldn't. So I tried to download the same area (same top left and bottom right coords) using the inbuilt function of maemo mapper and to my astonishment it said the area would take up 25GB of storage space as opposed to the 170MB it took with winmapper! I tried downloading it at lower resolution (~100MB) but even that crashed the N800. So my question (finally!) is this. What extra information is stored in the database file as opposed to single image files to make it take up so much more space? Also, is there any way to stop the n800 from crashing except choosing a smaller area? I guess I can't install mapper 1.x on OS2008 and there's no alternative for winmapper...

You could try RoadMap, that uses vectors instead of images, as Maemo Mapper does.

Try downloading higher zoom levels (say 15MB worth), then proceed to more detailed maps.

OK I'll try that thanks.

Just stumbled on "mmpcmapper". Is it any good? Anyone use it? If so, it's exactly what I'm looking for.

It doesn't store anything in addition to the map itself, except the coordinates of the map. The estimate that Maemo Mapper gives you just before beginning to download is a very rough estimate, typically off, but it shouldn't be off by two orders of magnitude (as it appears to be in your example).

As suggested, consider starting at the higher zoom levels (further from the earth) and working your way down. For example, I typically download the whole Earth down to Zoom Level 18 or 16, then America at 14, parts of America at 12, etc., all the way down to my local neighborhood at level 4. I usually skip the odds, to save space.

It can take a little experimentation to get used to, but ultimately, I prefer to download "on demand" by downloading maps "Along the route" before heading out on a trip.