My final talk of the day was title on the signup page 'Developing for the mobile', which led me to believe it would be a discussion of web applications for mobile devices, but the title of the talk on the day was as above, and focussed mostly on web content rather than application type interactivity. Despite not fully meeting my expectations, this was perhaps the talk where I learned the most new stuff.

Gummi started with a discussion of why mobile website development has been so much more difficult than standard web development. Mainly this comes down to standards - although 'desktop' web developers complain about inconsistencies between popular browsers, this is nothing compared to the great variety of mobile browsers and devices and also the different standards that have been implemented. He recommended that these days it was best to concentrate on cHTML for the Japanese market and XHTML for the rest of the world.

Mr Hafsteinsson's golden rule for mobile websites - KISS. Generally that cunning feature you've thought of which would be 'neat' rather than useful to users is a feature you don't need on your mobile site. There were then a sequence of slides with more specific tips:

• Use well formed markup - use the correct XML preamble and DOCTYPE declaration, validate your markup and specify character encoding. While it is feasible for a desktop browser to do a lot of processing to correct your markup mishaps, most mobile devices don't have enough spare processing power to deal effectively with invalid input
• Send Google a Mobile Sitemap - on the mobile web people don't (generally) type in URLs, because typing options are usually fairly restricted and/or awkward on mobile devices, there is a much greater reliance on search engines so you need to do everything in your power to help the search engines out
• Understand best practice - two sites specifically mentioned were the W3C's Mobile Best Practices and the dotMobi portal
• Test in emulators - it's not feasible for you to obtain every mobile device on the planet, so testing in emulators is a good shortcut. Some of the specific emulators mentioned were the NTT DoCoMo i-mode HTML Simulator, the wmlbrowser extension for Firefox, the OpenWave emulator and the NetFront emulator (which has a Linux version) and, of course, Opera which can emulate the phone browser in the desktop version.
• But don't just test in emulators - sites should be usable on entry level phones and provide an effective experience on mid-range devices. Be aware that these devices have far more limited physical features than your desktop development machine, things that work fine in the emulator on your desktop with 2Gb of RAM and a broadband connection might not work well, or at all, on a GSM phone with 64K of RAM. Again, don't overload your websites with features that overload more basic phones.

That was the bulk of the talk (actually relatively short), but there was a long question and answer session which covered the use of XHTML Mobile profile (and not Basic, as shown on the slide at the beginning) on .mobi websites and quite a lot of discussion on the merits and pitfalls of user agent sniffing (using, for instance, the WURFL device database). Gummi's advice was not to blindly adopt a sniffing approach, use standards for the most part and use sniffing to get round incompatibilities where appropriate for your users - generally think about your users rather than about the devices. Hopefully increasing use of standards in mobile websites will lead to better support of standards in mobile devices. The questions went on with some discussion of the Google mobile search and content transcoding (where Google automatically converts a website to mobile compatible format when you click on the link rather than sending the page directly), how this would become less necessary as more sites provided mobile versions of their content, and also a meta tag you could put in your head element to direct Google to the mobile version of a particular page (though I can find no mention of this elsewhere on the web, so if anyone locates it please leave a comment).

Overall an excellent talk despite being short, a bit high level and lacking code examples (which I know I've criticised other talks for, but in this case the high level information was very useful to me). Also the question and answer session covered a lot of extra ground, so 5 out of 5. If you are planning to get involved in the development of mobile websites I would recommend spending 45 minutes viewing this talk.