SonnyCooL (17 April, 2011)
MyBB is great, but it doesn't have smooth integration with Wordpress (just a bridge IIRC).
Seen a few wordpress blogs use this one.
I came close to putting it on a blog myself.
Mingle Forum Plugin for WordPress | Cartpauj.com
You can embed a small embedded forum as per your requirement.
You can see my forum though it is inactive currently but its just example..
Dental Care Tips
It is embeded with talkie.
you can also use nabber.