>a) privacy: most people, including me, like to keep their privacy >as is - and this might not be the biggest obstacle but it sure it >a big one.

privacy has not be addressed till now. But it could be done, for instance managing a list of trusted sites in the browser and sending user location only to them. Other solutions are possible and can be investigated. Remember that our project is really in its inception.

>b) type of browser: it only works with a mozilla based browser - >the percentage of mozilla browser users is still by far >outnumbered by MS IE.

It only works with mozilla NOW. I don't see the problem to implement the same in other browser. Any browser sends HTTP headers, am I wrong?

>c) hardware: you need a GPS device, or it won't work at all. - >the percentage of people that a) use mozilla and b) have such GPS >device and c) don't care about their privacy is what? 0.00001

Cost of GPS is dropping. You'll have GPS under your skin in few years (I'm kidding ...or I'm not?!). Let's see... a) use mozilla and other browser with HTTP headers. b) have such GPS c) willing to have location based services and able to handle their privacy with few clicks is what? 0.00001% mmm... if we consider 1 billion users it is at least 100 users. It is not a negligeable market:). But I don't think your estimate is very accurate.

>d) costs: it only works if web authors a) know about this and b) >like to support anything like this and most important, c) their >boss pays them to do so. - I don't think this is ever going to >work, because there are plenty of websites, with tons of JS >errors of no support for mozilla.

a) they'll know if it works. b) they'll like if it works c) already answered to that.

Best from Davide :)