Drawing blood with Twitter. (In the good way.)

Next time you start to feel that social media is awash in self-promotion and pointless minutiae, think about the bright spots like this Blood Drive Tweetup in Austin, Texas.

With only a few days' notice (and right around a holiday), the event drew a turnout of about 100 people — more than double the usual number of daily donors at The Blood Center of Central Texas.

The organizers — Austin Social Media Club, 501 Tech Club of Austin and others — used an array of social media tools to spread the word quickly. Just think what would happen if someone organized a national or even global version of this blood drive.

So who's up for trying a National Blood Drive Tweetup? Or at least one-upping Austin with a 200-person Birmingham event? Either way, I'm in.

Thanks to social media swami Chris Brogan for the heads-up.