Longitude and latitude have been formally used as a geographic coordinate system offset from the Greenwich Meridian since the International Meridian Conference of 1884 in Washington D.C.

As a spatial coordinate system, longitude (abbreviated as φ, or phi) and latitude ( λ, or lambda) work very well in defining a point on the surface of the Earth. But to gain further meaning from a long/lat pair you either need some clever algorithmics or you need to plot the long/lat point on a map which even then will yield information only as good as that which is rendered on the map itself.

Which is why I think identifier systems, such as Yahoo's WOEID, add so much value. A WOEID adds a linked web of rich metadata, describing not only a point with a long/lat centroid, but also reinforces the concept of a place, with neighbouring and hierarchical relationships.

Coordinates describe the where of a place, identifiers such as WOEIDs describe the how of a place but both conveniently (in a slight embarrassed, foot shuffling short of way) overlook the when of a place.

I take a lot of photos, most of which end up on my Flickr photo stream. While some of them are taken with a proper camera  (though some would say that my Lumix FX12 isn't a proper camera), most of them are taken with my iPhone, which doesn't take great pictures but takes pictures which are good enough and with the added bonus that I have it on me almost all of the time.

My photos all used to be publicly accessible and with an all rights reserved copyright on them but then I lost my Flickr innocence, which was a bad thing at the time and switched all of my photos to friends and family visibility. About a week later, when I'd calmed down a bit, I went through all of my photo sets; photos of my family and of home stayed out of the public eye and stayed all rights reserved. But everything else, I opened up and changed the license to some rights reserved using the Creative Commons Attribution Share-Alike license.

51° 31' 36.8364" N, 0° 7' 44.0466" W

Entering the longitude and latitude above into one of the many online mapping sites on the web will  show you the St. Pancras branch of wallacespace, close to London's Euston and Kings Cross St. Pancras rail termini and seems a fitting and apt way to write a blog post about WhereCamp EU, the first geo unconference to be held in the United Kingdom and in Europe.

The last week has been crammed with planning for and finally realising the first WhereCamp unconference to be held in Europe. More of that later but before WhereCamp EU, there was the London Twitter Developer’s DevNest.

Angus Fox, one of the organisers of the DevNest, had first got in touch with me last year after the launch of the Yahoo! Placemaker web platform that allows recognition of place references in unstructured text. Placemaker plus Twitter status feeds seemed an ideal candidate for a mashup and Angus was keen to get me to talk to his hard-core Twitter and social media literate developer audience.

Hyperlinks in the form of web links are the lifeblood of today's internet and world wide web. Examination of your web server's log files, either directly via tools such as Webalizer or indirectly via analytics services such as Yahoo's or Google's can show you who's visiting your web site or blogs.

But who's visiting your site isn't the whole picture; following a hyperlink is an active process. To complete the picture you need to find out who's linking to your site, which is a passive process.

If you're running a blog you may be able to use trackbacks or pingbacks to find out when a site links to you, but only if the linking site support the trackback or pingback protocol and then only if this is enabled on both sides of the ping relationship.

So what about those sites which don't support trackbacks or pingbacks or who don't want to be discovered that they're linking to you?

I'm sorry Facebook but your ad targeting systems are wildly inaccurate and reduce that valuable screen estate to the right hand side of my browser window to irrelevant line noise. Google's and Yahoo's ad targeting is pretty darn good but looking at Facebook right now offers me:

• Omniture Research; which Obama used, apparently.
• Free laptop from Vodafone Business; I'm not self employed so a business tariff is a non starter.
• Everyone plays Mafia Wars; except me and most of my friends.

I've never run or hosted my own search engine. I've run and hosted web servers, mail servers, proxy servers and caching servers (I'm even contemplating running my own URL shortener), but never a search engine. There was a time when I ran an enterprise instance of Alta Vista back when I coded for a living and was part of the team building Factiva.com, but that doesn't count.

If I had have run my own search engine I would have known just how important canonical URLs are and that having multiple copies of the same content hosted on different domains would cause search engines to penalise you and loose search engine ranking, fast.