I'm wondering if there is any open source GPS turn by turn software for the n800. I'm not opposed to buying if I have to but prefer open source on principle.

Yes search in the forums for the Maemo Mapper, is a really amazing application

ah ok from what I read that llooked like a topo application

It's not topo per se, but it can be. It will take any raster map and use it. It has to have an internet connection to get a route, but you can download the route before leaving, and get turn by turn directions while driving it, or you can use your cell phone on a data link for routing on the road. There are a couple of others in development, but AFAIK they don't do routing yet. I haven't kept up that closely, though, so they may be routing by now. Check the Maemo Garage for more info.

I would point you to Navit first, and then Roadmap. They are both still 'prebeta' if I understand things, but they are trying to do real navigation with turn by turn routing, using open source maps. They both seem awfully great to me, but I haven't installed them (since they are early versions they take some work to install if my reading is correct).

Again, if I understand correctly, Navit has more of a Europe and US focus, while Roadmap has a US focus. That may be due to the fact that US maps are open to the public, or due to the folks who develop them, but I distinctly heard some feelings that roadmap is really a US project for now (though their website indicates that they are trying to move beyond that) and that Navit is more on par with Europe and the USA. I think they both want to service *everyone* and it is only map access for free that keeps them holding to a geography.

Either way, they are open projects that will only get better, and they cost you only the effort to install them (unless you love them so much that you decide you can be a contributor!) Good luck, and if you find that one or either meets your needs, please post again to that effect (or if they don't meet your needs, I think that is a valuable post too)

Trying to add some useful links
http://wiki.navit-project.org/index....t_on_n770/n800
Roadmap: http://www.internettablettalk.com/fo...ad.php?t=17718
(If someone has better links, please post them, these may not be the most up to date.)

I'm looking forward to using Navit when it works --- looks promising, but it crashes whenever it connects to my GPS --- go figure. Would love to drop Maemo Mapper as I don't want to be connected to the internet to get routes --- you can preload before, but if you make a wrong turn, there is no way for maemo mapper to give you a new route. Navit looks like it will have onboard routing; i.e., no internet required.

Roadmap now supports OSM maps, so ought to work in the UK/Europe.

After a wonderful weekend without any small-scale maps (printer broke so no Google maps for me, plus N810's battery went flat), I'm going to do some experimentation with both Navit and Roadmap.

So far, Roadmap produces nice graphs (has a gui to download OSM map data, is there a command line option too, so I can do this over SSH?), though I can't for the life of me work out how to show the current location or get it to route somewhere (it does routing, but seems to be straight line routing between my random clicks).

Navit doesn't seem to display the map data I've given it; perhaps I need to hook the GPS up (am too far away from my Bluetooth GPS sat outside on the balcony) for it to move to my map area.

The only way to get autorouting and rerouting without an internet connection is by using vector maps. You can get free vector maps for the US from the Census Bureau, but they have limitations. They don't know about one-way roads, for instance, and mapping programs will happily route you the wrong way on an interstate highway, or any other one-way road. I've used Roadmap on the EeePC using these maps, and it works OK, but you have to be very careful with the route you get. It's technically impossible to get any routing from a raster map, which is what Maemo Mapper and most other programs, including Google Maps, use. Any routes have to be done by a server, which uses other means to get the route. Thus it will never be possible to use most free maps for autorouting, and most vector maps with real routing capabilities aren't free, and may never be. If you want actual routing/rerouting on the fly, you have to pay for it.

OSM maps are vector maps; Roadmap and Navit are both supposed to support routing.

Ah, that's the wrong attitude , assuming you have sufficient metadata in your vector maps (like road directions, and one day perhaps speed limits) there should be no problem creating a route - admittedly it may not be ideal, but better than nothing. And quite an interesting thing to work on too IMO.

That's a very big assumption you're making. The reason you have to pay is that the metadata isn't freely available. There are free apps, and free maps, that can do routing, but they don't have all the information needed, especially the data on one-way roads. If you're willing to live with the possibility of being routed the wrong way down these, then you can get by with free. To get that data, you have to pay, at least in the US, which AFAIK provides more free data than any other country.