I've been meaning to link to this since it was posted earlier in the year. Jens Alfke hopes for a decentralized future Web 3.0:
"Centralization creates concentrations of power, and that's dangerous. The people who run the servers have total control over your (and everyone's) data. They can snoop at it (however private it's supposed to be), they can sell it to advertisers, they can accidentally lose it, they can accidentally expose it to hackers."
I agree. Even for the best-loved centralized companies, like Twitter and Flickr, I want a copy of my data. If the first set of desktop tools to interface with web services were all about sharing and publishing, the next software generation will need to also effortlessly download and backup that data. Even usually careful programmers sometimes get it wrong.
Jens goes on to talk about CouchDB, including a link to this intro book. Looks good. Couch and other no-SQL database systems like Mongo are interesting technologies that I'd probably come up with an excuse to use if MySQL wasn't such a workhorse already. Related, for the Ruby fans in the audience: Phil Burrows on logging with Mongo.