I think it's useful to have a graphical representation of a user's rank, in terms of both posts and mod status. It's easier than reading the postcount and title. As mentioned, this is more for the benefit of newbies - the regulars basically know where everyone stands.
That said, the lemmings are too big presently - I find them distracting when reading posts. So maybe they could be shrunk to half size, like we did with the clam and frog smileys
. And can we put away the Christmas lemmings until December rolls back around?
Post-count isn't necessarily the best measure of a user's standing of course, but I suspect this place is less spammy than other forums
. I think the most useful distinction is between total newbies (eg. someone who posts one topic in Help and doesn't come back) and those who make regular contributions for a time. With that in mind, I'd make it so the first few ranks really easy to get (say, 2nd rank at 20 posts), and then have the requirements ramp up sharply after that. This would probably require more than the current five rankings.