Do you Tweet?

Social networking is now a necessity for writers, but for readers it seems to be more about community, and meeting in cyberspace people who like the same things you do, and want to talk about them. Every interest, no matter how esoteric, has a community, it seems, from hot-air ballooning to origami to sinus-sufferers.

But how is it working for you? Do you blog, do you twitter? Do you stumble, stagger or shelfari? Ten years ago I wouldn't know what the heck I was talking about if I said 'blog' and 'twitter', but now, along with Facebook, MySpace, Digg, Technorati, StumbleUpon and a million other social networking tools and sites, the internet is a bewildering forest of social networking trees... so how do you tell a spruce from a fir? How do you know which will work for you?

No... I don't have any advice, I'm asking!

Do you - any of you in the murder mystery reading and writing community - have tips on what works for you? Do you have a community to which you belong? Do certain social networking sites or methods find pages for you that you have stayed with?

I'm wondering in part because as a reader, I visit several sites and blogs daily or every few days, and as a writer I blog, comment, read and follow many other blogs.
I'm curious about ones other find compelling or informative.

I'm also curious about how your choices in reading matter are informed or changed by social networking. Do you read author posts? Does an author's online presence change how you view him or her? Do you just look for books on amazon.com, or use publishing house newsletters? SYKM? The 'Cozy Mystery List' blog?

What works for you? Inquiring minds want to know.