For anyone out there who, like me, has been looking for a good open source map program that also works offline, here's my experiences.

modrana: far and away the best user interface, and now that I can use offline maps, the best thing out there for me.

navit: a very good effort, and if some kind soul comes up with a navit.xml (their config file) that has sensible defaults, it'll be a real runner-up. My problem with it right now is that text sizes have to be set for every zoom level, there's no easy way to guess what zoom level I'm on, so it's a matter of guesswork and trial and error to try to find sensible values. So far, I haven't managed.

monav: an excellent front-end for OpenStreetMaps, very fast. User interface not quite to modrana standards, but okay. Offline maps generated using a vector program which shows real promise, but ... but, but, but, right now it only draws very few of the features so it's functionally useless offline.