No…you cannot integrate Wordpress in CodeIgniter. That question is very ridiculous. I don’t know of any blog software off the top of my head written in CI, however you can create a basic one yourself pretty easily.
Here is the Blog in 20 minutes video for CI. It is a little old, but the basics are the same: http://codeigniter.com/tutorials/watch/blog/
Dan
Actually Dan, your answer is very ridicilous! It would be perfectly doable. I did something similar with a site of mine! I would use wordpress for all the back end stuff and CI for the frontend parts. The one thing I had to do was write some models to grab the data from db… Piece of cake! The thing is, Everything is possible with CI 😊