The slides from Matt Biddulph’s developer talk about Dopplr and smart integration with the rest of the web are now available on Slideshare:

This talk was given at Future Of Web Apps 2007.

Several people have asked us for a way to list their trips on their blog, so today we’ve added a blog badge system. Visit your account page and follow the link to “Add a Dopplr badge to your blog” to get the code to paste into your templates. Written in unobtrusive Javascript, it only uses a couple of lines of HTML and will work with any blogging system as it requires no server-side plugin.

You can also customise the display; if you want us to be a little vague about dates, to hide future trips and only show your current location, or even to hide the badge from visitors who aren’t fellow Dopplr travellers, that’s fine by us.

This week the Future of Web Apps conference rolls into London and brings many Dopplr travellers with it. Matt Biddulph, Dopplr CTO, is speaking on Thursday about how we integrate with the rest of the web. He’ll be explaining how microformats, OpenID, Facebook, social network portability and other new technologies can be used by developers to extend the reach of their applications beyond the websites themselves.

Looking at the aggregate statistics from our database, people are travelling from more than 80 different cities in 20 different countries. London is always a busy city for visitors, and not everyone will be coming here for FOWA, but this week the number of trips is more than double the norm.

If you’re at PICNIC in Amsterdam this week, come and join Matt Biddulph, Marko Ahtisaari and fellow travellers for a drink on Thursday evening. We’ll be in Café De Jaren from 8pm onwards.

It’s a bit rough around the edges, but our new API is now ready for intrepid hackers to play with. Via the API you can do nearly anything you can do via the website: add trips, find cities and query information from your network of fellow travellers.

For authentication we use a similar system to Google’s AuthSub - so similar that some Dopplr API implementations are based on existing Google wrappers. We’ve contributed a Ruby wrapper, and developer friends like Simon Wistow (who had early access) have contributed Perl and PHP versions. Data comes in XML and JSON flavours, and documentation is a work-in-progress on the Dopplr Developer Wiki. Feel free to add notes to the wiki, or link to your own projects. Send us plenty of feedback and we’ll help you get your apps on the road.

This week, after a dinner conversation with Stowe Boyd, I’ve been adding new features to our Atom feeds.

From your Account page, you’ll now find a link to a feed that just contains your trips (optionally with past trips included too). Why would you want this? Because the feed contains a lot of machine-readable information. Here are some ways to use it:

Put your itinerary on your blog sidebar

Most modern blog systems will take an Atom feed URL and import the entries as a sidebar on your blog:

Map it in Google Maps

Google Maps understands the GeoRSS entries in the feed. Here’s all the trips I’ve shared since Dopplr began in early 2007:

View Larger Map

Export from NetNewsWire to iCal

Just like the main Dopplr site, the new feed uses the hCalendar microformat which some feedreaders can use to import trip details into calendar software. Here’s a screenshot of NetNewsWire importing a trip into Apple iCal:

Use your Javascript, your Yahoo Pipes and your imagination

The examples above are just a few suggestions I came up with this afternoon, and I didn’t even mention the Google Data-compatible event data. With a bit of extra work, I’m sure you’ll come up with something much more interesting.

Remember that the URL for your trip feed is personal to you - it’s got a code on it that no one will be able to guess. So think carefully if you’re going to embed that URL in a public widget (like I’ve done with mine in the Google Map above). Once someone has the URL, they’ll be able to follow your trips through that feed, even if they’re not a Dopplr member. Personally I don’t mind if my trips are visible in public, but you might feel differently. Code carefully.

Since we launched our updated place database last week we’ve been working on a number of improvements which have just gone live.

A couple of people pointed out that we still don’t list some important cities (including Hobart, the capital of Tasmania). On advice from Marc of Geonames, we’ve been able to add all capitals cities that they know about in their database. We’ve also made capitals the default selection whenever there’s a name clash. For example, if you type Hobart then we’ll assume you mean Australia and not Hobart, Indiana. I should add that if you’ve listed a trip to Hobart, Indiana before then we’ll remember that next time and use it next time in preference.

Secondly, we’ve had a few long-standing naming confusions in our database. Geonames uses local naming whenever possible. Outside Ireland it’s not well-known that Dublin is really called Baile Átha Cliath. To avoid confusion, we’ve tidied up several such names. This should make adding trips to Moscow, Prague, Rotterdam and Frankfurt a little simpler. We haven’t forgotten the original naming - we still do the right thing if you search for Москва - but the defaults are now English names.

This week, Dopplr got a big upgrade in the way it handles places. Firstly, we’ve expanded our coverage of locations to nearly 200,000 cities worldwide. We now list every place that has a population figure in Geonames. We’ve still got a way to go in coverage, but it’s a huge improvement. We’ve also reworked our city URL structure and our search pages. People of Llanfairpwllgwyngyll, rejoice.

The bigger the location database gets, the more potential there is for complexity in our UI. We’ve handled this with some rather pleasant and appropriate uses of Ajax and geocoding services. When you add a trip to a place like ‘Oxford’, ‘Cambridge’ or ‘Springfield’, we check your trip history and the most popular trip destinations and make a suggestion - perhaps you mean “Cambridge, United Kingdom”?. If we’re really stumped, we turn to Google’s geocoder, like so:

1. Google, where is “Sherman Oaks”? (Sherman Oaks is a district of Los Angeles)
2. Google says “Sherman Oaks, CA, USA at 34.15116,-118.44456″
3. We look in our database and ask, what�s the nearest thing to that location that we know?
4. We find Beverly Hills, CA, USA at 34.0736,-118.4 and offer it as a suggestion.

This also means that you can add trips using any location style that Google knows about - postcode, zipcode, airport IATA code and many more.

UPDATE: We’ve made a few more refinements in response to comments below.

Today we’re welcoming our first full-time employee to the staff at Dopplr. Tom Insam is joining us at our London office as a developer.

Tom worked for the last four years at Fotango where he was a senior engineer on the Zimki JavaScript application development platform. He is a long-standing member of the Perl community and knows way too much about Unicode. He is also the author of the first known Dopplr mashup. We’re very happy to have him.

As some of you have noticed, we’ve had a few hours of unplanned downtime recently. Every few weeks we’ve had an unexplained server outage that seems to be caused by a hardware fault. In order to investigate and fix it, the admins at our hosting facility need to take the service down for a few hours and run some tests. I’ll know later today exactly what the timings will be and I will post an update here.

UPDATE: dopplr will be down for two hours at 2pm BST.