I'd love to help out. I'd definitely go for this function. Nokia has iSync plugins for the phones but not the n800 i find that strange.

Re Geoclue: It seems to me that what is needed is a backend process based on a database (mysql? sqlite?) which can query/store the geoclue/gpsd hardware output, and then user frontends can query that database. The backend can keep running gps output in tracking mode or present position in static mode as set by the user. The frontend program deals with retreiving waypoint data (and storing names of waypoints) and all calculations or with matching processes like gps position with desired positions etc. The frontend would fork the execution of programs as required (eg gps now says we are "here", so sound an alarm.) This involves a proximity comparison between waypoints..ie bearing and distance <= x. The reverse is like an anchor alarm.
The database needs to be able to keep lots of waypoints and allow easy searches by lat/lonf, name, date, time, type etc. I can see the N810 being a great sailing navigational platform as well as a great general navigation platform.. All handheld and car GPS are useless at real navigation since you cannot input arbitrary waypoints or define them by calculation or do arbitrary calculations of bearing and distance etc. The N810 allows us to do the computation, but you end up with lots of waypoints which need to be recorded...Thus the database requirement. The database also needs to store calculated information..bearing and distance vectors, or the order of passing waypoints etc.etc. The database is separate from *what* you need the data for...In the example of mileage, you would want to be able to easliy create a 'start waypoint' of type mileage, and a summary waypoint for the sum of the intermediate waypoints (at arbitrary spacing/times) together with a destination waypoint which is the end of the trail...and the user needs to be able to name that grouping of data easily:
"Nov 28, from 'office' to client's (jaysin22) office, 22 km, 9:12 to 9:56 am. 'Live' waypoints need a date/time field. Static waypoints (map datapoints?) don't need/have that.

Anyone know was is embedded in the N810, if anything? Or should we just go for mysql?

Regarding the geotag http header idea, people should google 'mozilla microformats' and see what is being done for firefox 3. Same idea is usable on N810 as the browser is based on gecko...Let's no re-invent the wheel.
Then instead of a fixed file with position data, the browser could use a selected waypoint from the waypoint database for its data, as very often the 'present position' is not the locus for the search. ("I'm at the airport...I want a mexican restaurant within 4 blocks of King and Adelaide Streets.".)

Why do you find it strange? There is no PIM on the Maemo devices. What do you want to sync it against?

Actually, something I've always thought was strange is that if you have Nokia's PC Suite installed (PC Sync for handsets) and you connect the N800, you get a popup that says "N800 Connected in non-compatible mode". This is the same message you get when you connect a phone in mass-storage mode. Hmm.....

Yeah, that message will come up any time it doesn't detect a PC Suite-compliant connection on the other end. If you use the Nokia Media Transfer application on OS X you have to use PC Suite mode on an N-series handset (or e-series) for it to work -- it has a protocol it expects on the other end.

Doesn't surprise me that it says non-compatible mode, just means it doesn't speak PC Suite

Actually, that was similar to my proposal too. We need to get together on this! I was thinking of having a website which tracks your location too, and automatically logs (or not) who you meet, when you met them, etc etc.

Great! :-)

I started the OLSR project on garage to package it with the soon to be released PAA plugin/server for auto mesh IP config... Though, I'll be busy with that part for a while i guess. Anyone wants to try and run I2P over this? :-P

Anyway, keep me up to date, I'd be curious to see geolocation over mesh integrated in MaemoMapper with a video/voice chat when you click on a random stranger or friend... (just throwing random ideas here, wonder if this can be standardised to other platform too... ;-)

I'm really into device 2 device ideas (research?) without any middle man/server though...

cheers!