Post-ID in Permalink or not?

Hi everybody,

A question about changing permalinks. I’m thinking about changing my permalinks. It’s only got the post-name at the moment and my suspicion is that adding the category to it would be a big improvement in SEO.

Now I’ve heard stuff about putting Post-ID or some kind of other number sequence in the pemalink structure. For example the New York Times has the date of the post in the permalink.

My question is therefore. Should I also put in some kind of number (e.g. the Post-ID) in the permalink?

Thanx for the replies!