If you don’t have Trackbacks and Comments enabled on your blog, do it. I allow Trackbacks and Comments on all my blogs. I do however moderate them to keep out spam.

Not only should you allow them on your own blog. You should do Trackbacks as often as possible and you should Comment on other other post as often as you can.

A Trackback is the method of informing a blogger that you are linking to and using information from his post. Both Trackbacks and Comments are just one tool to also help you with your SEO.

The fellow are additional reasons from Problogger why you should be doing Trackbacks and Comments.

• Leaving a comment or two makes your name familiar and lets the blogger know that you read his or blog. You become a person, a person who is interested and interesting. Leaving a trackback before you ever comment can look like you are standoffish or too busy to comment.
• Leaving a trackback on the same post where you’ve left a comment can work really well, if you are truly interested in the dialogue and the topic. Think of it as a real conversation, that you might have had with a fairly new friend. If you were truly engaged and thought of a new point on your way home, you might shoot him an email or IM to pass it along.
• The track post that you write shows that you took the conversation at the original blog one step further. Almost everyone would think that’s a compliment, sending a trackback is a lot like saying ‘You’ve got me thinking, and I’m telling others good things about you.’ Who wouldn’t like to hear that?

Good advice to follow. So, go forth and Comment and do Trackbacks and increase your own traffic.