Content aside, some of the unexpected surprises of the IxDA conference so far have been some structural decisions that make a lot of sense.
First off, a one and a half day long "pre-conference period" of workshops is built in for greater flexiibility. The official start of the conference is mid-Friday, but attendees can arrive as early as the previous morning and attend any of a dozen or so different add-on classes on more specific topics, allowing the experience to be a general networking schmoozefest, or a more directed skill-builder.
The workshops, moreover, are exceptional in their length (4 hour sessions) and interactive content (though perhaps unsurprising considering the clientele). Poking heads into rooms yields some surprising vistas: groups gathered around stick figure sketches, arguing over strategies, prototyping websites on pen and paper, etc.
It's also one of the most Twitter-enabled functions we've yet come across -- again, not such a surprise considering the audience -- but the degree to which tweets have been integrated into the fabric of the conference is eye-opening. The multiple hashtags affiliated with the various sessions generate a rich document of every discussion, and often erupt into their own para-discussions, as happened earlier today during John Thackara's confrontational, thoughtfully considered keynote talk. There are also monitors scattered throughout the venue, displaying recent postings from attendees Twitter and Flickr streams, leading to some strange meta-discussions and time delays that just adds to the futuristic feel of the whole affair.