Brian Fling from Blue Flavor ran a great workshop called "Designing for Mobile" (you can view the slides here). He told us about the fundamentals of the mobile "ecosystem," and shared myths and terminology from the industry. The slides are worth reading through for the "jargon" definitions alone.
When he explained the mobile ecology to us, I thought the coolest thing was when he explained some of the differences between our mobile culture here in North America as opposed to Japan or Europe. First of all, Japan is a very small place, and a single cell tower can have millions of subscribers, so there are some hardware advantages over there.
Secondly, in Europe, landlines are assigned from government telcos, so it's very slow (sometimes months) to get a phone number, but you can get a mobile phone in an hour. SMS (text messaging) became prevalent because it was cheaper to send a text message than a voice call.
Third, he pointed out that North America is the only mobile culture that gives free phones in exchange for a service commitment. In Europe and Japan, they pay for their phones, so there's a higher upgrade rate.
Finally, he said that there was a difference in the reasons for adopting mobile technology. In a train-based culture (like Europe or Asia), the mobile IS the computer. Most people don't have computers at home, so they use mobiles on trains. Here, we'll always have (and prefer) home computers, and we drive more, so there's less demand for mobiles to replace computers. Instead, they will suppliment and extend desktop capabilities.
As far as actually designing for mobile phones, he gave several great tips. Like the browser world, you can't support every possible hardware/software combination. Only it's much worse, because there over 30 different browsers and more than 200 devices in the US alone. But it's not as bad as it sounds, because many mobile devices are similar, with the differences being the software the carrier puts on them (like buying a Razr from Verizon instead of Cingular). His advice was to pick five. Five browsers, and five phones. If you pick carefully, you can choose five that are reasonably mass-market and common to your users, which will be good representations of the larger market. He also advised against supporting smart phones or PDAs, since they have less than 20% of the market share, with smart phones taking something like 15% and PDAs have less than 1%. As a result, you should pick your five from the mass market phones that people get from their carriers.
He talked a lot about "the deck," which is the industry term for the first screen the user sees when they get online using their mobile device. It's like a homepage, but it's owned and managed by the carrier, and is highly competitive. It's also unlikely that you'll get a useful position on the deck unless you're a huge company like Rolling Stone.
We did spend some time discussing specific technologies for mobile pages (WAP, J2ME, WML, etc.), but this doesn't really matter until you know your target market (for instance, if all your target phones support WAP2, you have more capabilities than if you have to support older phones that only do WML.)
If there was one preconception that he wanted us to get rid of, it was the idea that mobile development is like the Wild West, with no standards at all. In fact, he said, it's the opposite - there are standards for everything and they're more strictly enforced than on the web. The downside is that the standards are difficult to find, because there are few books on the subject. I would argue that a standard is nearly impossible to find might as well not exist, but that's just me being picky.
However, what was incredibly useful was hearing the pros and cons of maintaining a separate mobile web page. Without getting too into the "Mobile Web" vs "One Web" debate, what it boils down to is that you have a variety of options, ranging from doing nothing (trusting the mobile browsers to learn how to handle your normal website), to creating a separate page specifically for mobile devices. The message I walked away with was that unless you're offering some content specifically for mobile users (such as google's mobile pages), you're better off maintaining a single page, and offering a mobile-specific stylesheet (again, using the "just pick five" philosophy).
He was very excited for the future, and maintained that we're just one "killer app" away from a huge mobile boom. He specifically mentioned Location-Aware applications, which use GPS in your phone to give targeted content, like searching for local places to eat in a city you don't know. He predicted that Mobile will revolutionize the way we gather and interact with information in the next three years, and jokingly referred to this as Web 4.0, with an apology to Zeldman (who had already claimed Web 3.0).