Good folks from the Nokia Maps Team just announced the very first release of Nokia Map Loader for maemo devices.
Just like the version for Symbian devices, Nokia Map loader for N900 allows you to simply sideload maps to your phone directly from Nokia maps server through your computer, rather than over the air which is especially useful if you are planning on travelling to a new area you are unfamiliar.
This way, you can save a lot on your mobile data service costs and save time downloading map data over-the-air as you go.
With maps for more than 150 countries worldwide, there’s a lot of data available for download for FREE and with Map Loader whole procedure will be faster, cheaper and simpler! MapLoader allows you to download map data for whole countries or areas, so that you don’t need to use data connection on the road.
Procedure is quite simple, download and install Map Loader to your PC, then download maps and places you need to and finally transfer it to Nokia Maps on your mobile device.
ok, to be fair: I'm using OSX, 10.4.11. Non-operation was to be expected. Happily I also have the maps copied already, so this is just info for those who have a similar PC.
do a forum search, there's lots of info on how to make map loader work on n900 - XP works out of the box, but IIRC you have to run vista 64 bit in XP compatibility mode for it to work. Worked fine for me on XP when I did it a while back, but I think only USB mode is supported for n900 (ignore the prompt objecting to it). Oh, and bring a good book to occupy you - the d/l & transfer for Europe took ~2 hours to complete :-)