A long time ago, I belonged to a project called consume.net in London. Broadband was very expensive and wireless technologies were coming out, so the geeks had a little think and the dream was hatched: a free wireless network in London. The consume website has a good summary of what it was like at the time. There was great interest, a big mailing list and meetings with 50 people. I remember turning up to a couple with good intentions but not really being able to help. There were discussions on routing protocols and antennas. A few nodes linked up, but nothing really happened and instead DSL arrived on the scene and got cheaper and cheaper, so consume.net never really made it.
My sister lives across the street but we couldn't quite get wireless across as we live in basement flats. Apple came out with AirPorts which supported wireless distribution system which I never tried out as they were too expensive. She eventually got DSL.
I recently purchased a 3-pack of Meraki Minis, which are ridiculously cheap little wireless mesh machines. Connect one to the internet, place a few around and your wireless cloud magically works. They provide a cute little dash board so you can see my little mesh network. It's cheap, it's easy. The technology has arrived. Meraki is based on the MIT roofnet project, they've just had funding from Google and Sequoia Capital and they are giving away routers to wifi up a square mile of San Francisco.
I'm really happy about this as it's small, cheap hardware which just works and I reckon it's going to change everything. I'm going to use this at my parent's house and in a few other places. Would this be useful for conferences?