A few Nelly-thoughts on blog commenting:
1. When appropriate, answer your comments within your own posts. It's fine to answer a comment on the commentor's blog (if they have one), or privately by email, but, that sort of takes away the fun of allowing everyone else in on the conversation. And it confuses the hades out of those who read comments as part of the postal reaction.
2. Read other blogs, and leave comments! You'll find yourself deep in a web of thinkers (or jokers, for that matter), and you'll likely gain some new readers, too.
3. Delete spam comments as soon as possible. I get one every once in a while. Other folks have written up whole posts about the spam they've received. Spam comes in multiple forms. Andrew Jones' anti-spam stuff is a riot.
A friendly note to Lurkers (AKA. you beautiful non-commenting folks):
I like you. Read on. You don't need to say a thing. But if you get the urge, I'm brushing up the welcome mat for you.
(Graffiti photo by Duncan)