Multiple exposures for HDR shots

Some of the most beautiful HDR photographs I've seen have blended as many as 9 exposures to get the final picture.

My D90 obviously will bracket but I don't believe it will bracket more than 3 shots.

So my question is this. How does one achieve 9 exposures without causing camera movement from adjusting exposure settings? My only answer would be a very stable tripod.

Any tips?
--
John