Social media diseases

I'm going to be speaking next week at Gnomedex, a premier tech conference held annually in Seattle and run by my friend the übergeek Chris Pirillo (and I mean that in a good way). I'll be talking about the spread of information and misinformation through social media, specifically Twitter. Remember the Texas fireball, and how the (wrong) idea that it was debris from a satellite collision spread like wildfire on Twitter? That's the sort of thing I'll be discussing. I'm also going to talk about other social media/networks like Digg and Reddit. I happen to find both of those sites useful, but both have their disadvantages too. This blog gets linked commonly from both, and I'm looking into trending and such on them. But I want to get opinions from people who have used one or both of them: what do you like and dislike about them? Which one (if either) is easier to use, has more reliable commenting, links to better stuff? I'd post this on those sites, but that would be like walking into an Apple store and declaring IE 8 to be the best browser ever. I prefer to keep any firefights local, thankyouverymuch. So let me know what you think in the comments below! I can't promise to use anything specific in the talk -- and I'm sure I'll be able to make some general observations based on what y'all say -- but if you have specifics, let's hear it!