What ladder system do you use?

I was wondering about what ladder system everyone is using.  When I created my ladder system, I had a hard time deciding how many posts were necessary for the members to jump to the next level.  I finally came up with something, but I want to hear what other people are doing.  It may help some people who are just starting out, and I may decide to tweak mine after I hear how other people do it.

Here is the ranking system I decided on CaribbeanChoice.com Forum.  I decided to use a pirate ship theme for the rankings and I am using the Invision skin for the stars.

 Lurker - 0 Posts (0 Stars) {Invisible .gif}
 Newbie - 1 Post (Faded Star)
 Landlubber - 3 Posts (1 Star)
 Mate - 40 Posts (2 Stars)
 Warrant Officer - 200 Posts (3 Stars)
 Quartermaster - 1000 Posts (4 Stars)
 Captain - 2500 Posts (5 Stars)
 Commodore - 5000 Posts (6 Stars)
 Admiral - 10000 Posts (7 Stars)

I wanted to make Commodore and Admiral very hard to get, but still possible.  Right now I have Moderators with 6 Stars and Administrators and Senior Staff with 7 Stars.  Once people get close to 6 or 7 stars, I will change administrator stars to red instead of blue.  But until then, I will just use the blue 7 star ranking.

I also decided to give lurkers 0 stars and people who posted only one or two times a newbie faded star instead of starting them with 1 star.  There are some people who do a drive by posting and never come back and I didn't think they deserved a full 1 star ranking until they were part of the community.

So, what do you think?  Any suggestions from people who have been running a forum for awhile?  And what are you using on yours?