For any GPS, the first fix after being moved hundreds of miles can take a long time, 5-15 minutes depending on conditions.

The N810 after first fix can take 2-3 minutes. Not moving and open sky is better. The GPS is fairly sensitive, but isn't the best because it has to be small and use little power, but I've gotten fixes near windows indoors. I'm surprised at how good it does that, and bluetooth, and wifi given the package size.

My BT GPS is much better.

http://www.buygpsnow.com/GlobalTop-G...-Off)_914.aspx

It gets fixes even indoors (including WAAS). Paired easily with the n810. Under a minute to a fix, usually WAAS well under 3 minutes. $50 with shipping. Well worth it. But if you've seen any external GPS, it usually has a just under one inch by one inch antenna. There's no way to put that into an n810, however there are GPS repeaters which might work too, but wouldn't be better than the above.

A thin version of the GPS is here:

http://www.buygpsnow.com/Product/Glo...unt)__925.aspx

Semsons.com has the first one, and there may be other choices, but I've gotten several.

And the N810 will work at 5Hz. I need to update a mapping program I did for the Zaurus that used US Census maps (Qt - sigh), but plotted everything and used small but fast compression. All roads, cities, lakes, parks, etc. would fit on the n810.