Dave Winer has released a cool experiment into the world: Twittergram. It's a voice version of Twitter (more coverage): You record a brief audio clip (200K max), and Twittergram puts it on a server and creates a Twitter post (a "tweet") that links to it. Twittergrams can be posted to your own personal Twitter account as well as to a public collection of Twittergrams (mobile version).
Initially (last month), posting a Twittergram required that you record an audio clip, then upload it via Twittergram.com, but now there's a phone interface so you can post from your mobile. Sign up for it here. It's the way to go: You can voice-Twitter while on the run--or on the drive, although I can't in good conscience recommend that--if you don't want to type a Twitter on your handheld gizmo.
Twitter.com links to Twittergrams via short URLs. I'd like to see Twitter embed a Twittergram player (maybe this is a feature that PowerTwitter could add), which would make for a better experience. It's likely one or more of the Twitter applications will do this. Likewise we might see soon an app or site that enables the quick recording to 'grams from a Web site.
Twittergram is a lot of fun. It could also be a very useful tool for citizen journalism. The service currently restricts people from posting more than one 'gram every 10 minutes to combat spam, but this could be dropped or modified for registered users, I imagine.
Is Twittervideo next?