I've CC'ed this to the OpenGuides developers' list so people can comment.

On Fri, Mar 12, 2004 at 03:45:02PM -0800, karlis wrote:

I think the best way to do this would be some GPSter-ish API for the openguides code so that user clients can poll openguides directly. Each city maintains it's own database/wiki/site?

Yes, that's right. Some of them live on the same machine, but most don't.

Are they linked in any other way, codewise, ie, is there a coordinated list of operating openguide installations?

At the moment, no. It would be a nice feature, I think, to have something like the InterMap (http://www.usemod.com/cgi-bin/mb.pl?InterMap) idea so you could say "blah blah the [Paris:Arc De Triomphe]", or something like that, probably located on openguides.org that could be polled for updates.

What's the minimum location info that each node will have? Postal code?

The minimum is actually zero - there are no mandated fields, because not every node is actually geospatial in topic.

How do the queries like "Things within 500 metres of Piccadilly Circus Station" work at the data level?

GPSter is really based on lat/lon coordinates (as the name might suggest), so the key would be the translation of openguide nodes into lat/lon positions. After that, moving the data around is easy.

At the moment, that's done by making calculations based on Ordnance Survey coordinates that have been entered for the nodes, because that system defines a convenient grid that's easier to manipulate for those calculations than lat/lon figures - none of this tricky business with oblate spheroids. We're very aware that this is proprietary to the UK, though, and are looking into ways to replace it. In the last day or two, someone brought the UTM system to my attention, and it seems to be a very good candidate (http://search.cpan.org/~grahamc/Geo-Coordinates-UTM-0.03/UTM.pm).

There doesn't seem to be a "click on the map" style interface for locating stuff.

Not yet, no, partially because of the insane cost of map data for this country (for example: http://www.ordnancesurvey.co.uk/oswebsite/products/10kraster/pricing.html). We'd be very interested in having a map interface. Ivor Williams (who'll read this on the list) is looking into doing visualisations of the stuff in an OpenGuides database.

Are there any north american projects similar to openguides, or is this just very new?

Well, we've been around a couple of years but people have only started contacting us and making their own sites around the world for the last few months. There's a newborn OG install for San Francisco as of the other week (http://sf.openguides.org/). Similar projects I know of are Wikitravel (http://www.wikitravel.org/) and World66 (http://www.world66.com/), but they're not particularly North American. There's also a New York restaurant guide thing that's fairly similar in idea, but I'm damned if I can find it right now.

Best,

Earle.