One of the great things about the combination of maps, geo, location and London is that roughly once a month there's some kind of meetup happening in the city on these themes. One of the longer running players in this space is the Geospatial Specialist Group of the British Computer Society which is being relaunched and reinvigorated as the Location Information SG. Earlier this week I gave a talk, but what to talk about?

It didn't take too long to come up with a suitable theme. In my current day job, consulting with open data specialists Lokku, I come across the benefits and the challenges in using open data on almost a daily basis. One of the earliest lessons is that nothing is simple and nothing is straightforwards when you bring licensing into a field and open data is no exception.

A standard WordPress install is incredibly powerful and flexible. For a lot of people, WordPress out of the box plus one of the stock WordPress themes is enough. But the possibilities for customization are endless; you can add plugins and other themes. Sometimes these do just what you want. Sometimes you need to ... tweak WordPress.

A very high proportion of the customization advice you'll find on the web starts with these lines ... add the following to the end of your theme's functions.php or even worse, advises that you modify the source code of your theme or your plugins. This is bad for many reasons:

• Editing your theme's functions.php makes theme specific customizations; change your theme and your customizations will no longer get loaded.
• When your theme and plugins get updated you'll find all your careful hand crafted customizations get overwritten and lost.
• A lot of theme and plugin authors won't offer support for changes you might have made to the source code.
• Your customizations might work; but you might also inadvertently make some other changes which will stop things working.

WordPress doesn't yet support a way for site specific customizations to be made and loaded without touching theme, plugin or core files; that's why I wrote WP Customizer and that's what this plugin is for. When WordPress does support such a way, this plugin will thankfully be obsolete.

Back in February of this year, at the height of the madness that was the Vaguely Rude Places Map, Ed Freyfogle from London's #geomob meetup got in touch and asked me to come and tell the story behind the map. This is that story.

And so last night, in the Chadwick Lecture Theatre in the basement of London's UCL, after listening to some amazing presentations on building a map of mobile cell tower coverage, of building a seismically powered alternative to GPS and a whole host of other great talks, I took my place on the podium and started where any good story needs to start ... at the beginning.

Yesterday, Google launched their Maps Engine Lite beta; a way of quickly and easily visualising small scale geographic data sets on (unsurprisingly) a Google map. The service allows you to upload a CSV file containing geographic information and style the resulting map with the data added to it. I thought I'd give it a try.

I turned to my tried and trusted data set for things like this; a data set I derived from a Flickr set of geotagged photos I'd taken of the London Elephant Parade in 2010. It's a known data source and I know what the results of this data set will give me; it lets me do a reasonably meaningful visual comparison of how a particular product or service interprets and displays the data.

Last night I made another map. It tries to answer some of more perplexing and confusing facets of the geography surrounding the world's 9th largest island. I mean of course Great Britain. No, wait. I mean the United Kingdom. No, wait. I mean Britain. Or do I mean England? See, it's confusing.

• So if the ISO 3166-2 code is GBR, how come the country is called the United Kingdom?
• But if England is a country and the United Kingdom is a country, how come England is part of the United Kingdom?
• What about Scotland, Wales and Northern Ireland?

This isn't the first time I've covered this topic. The first time was for a post on the now defunct Yahoo! Geo Technologies blog entitled UK Addressing, The Non Golden Rules Of Geo Or Help! My Country Doesn't Exist. The ygeoblog.com domain is now long gone and redirects to the Yahoo! corporate blog but I was able to reproduce this post here and it's also captured in the Internet Archive's WayBackMachine. The second time was when I made a variation of The Great British Venn Diagram. But this is the first time (though probably not the last) that I've used a map, which is odd as this is something that's tailor-made for a map.

Over the weekend I made another map. While I don't think for one moment this one will be as wildly popular as my last map was, this one is just as satisfying and a whole lot more personal.

At 8.01 PM on the 11th. of October 2009 I checked into Sushi Tomi in Mountain View, California. This was my very first Foursquare check-in. Since then I've checked-in on this particular location based service a further 12,394 times. Each check-in has been at a place I've visited. As this is a location based service, each check-in comes with a longitude and latitude.

This sounded to me like an ideal candidate for a map. But how to go about making one?

Oh people of the interwebs; you are indeed a wondrous thing. If you build something and put it up on the internet, you've no expectation that anyone will see it, let alone look at it. But it appears that the combination of innuendo and some vaguely sounding rude place names (actually with some very rude place names) seems to be something that the citizens of the internet actually like.

The map hit the internet at maps.geotastic.org/rude/ around lunchtime on the 6th. of February; since then, several things have happened.

Firstly, Eric Rodenbeck, the CEO of Stamen Design, whose map tiles I used on the Rude Map, dropped me an email to say he liked it. I'm a massive fan of the cartography that Stamen produces and this would, alone, be enough to make the making of the map worthwhile.

But then, the URL of the site started proliferating over Twitter ... including Jonathan Crowe, author of the late and utterly lamented Map Room blog.

No-one can really define what being British is, though many have tried. One thing that lots of people do seem to agree on is that part of being British is a love for and an appreciation of the British sense of humour. This can be roughly and with a sweeping generalisation said to consist of equal parts of finding fun in everyday situations Peep Show), satire and parody (Have I Got News For You), social awkwardness (The Office), surrealism and nonsense (Monty Python) and innuendo (the Carry On films).

Focus on that trait of innuendo for a moment. Could you possibly combine the British fondness for innuendo with geography and put it on a map? It turns out you can. So I did. It may be vaguely NSFW but there's real geographical data behind this.

If you're an avid Foursquare user you can already display your last checkin, visualised on a map, in the sidebar of your WordPress powered site with the WP Quadratum plugin. Foursquare, checkins and maps ... what more could you ask for? Maybe the answer is more maps.

Version 1.1 of the WP Quadratum plugin, which went live this morning, now has added maps. The previous versions of the plugin used Nokia's maps, because I work for Nokia's Location & Commerce group and I wanted to use the maps that I work on. But if Nokia's maps aren't the maps for you then how about Google's, or maybe CloudMade's OpenStreetMap maps or perhaps OpenLayers' OpenStreetMap maps.