I'm stealing this idea straight from these four guys (1, 2, 3  - and 4 - thanks Emil) and adapting it to the world of SEO/M. Here's my take on what the various levels of knowledge are in the search microcosm - I've tried to provide examples as well:

Level 1: Confused
New website owners or developers who think to themselves... "Hey, don't I need meta tags to get Google to like me? And maybe I should buy that $19.99 submission service to the top 40 search engines - after all, if it ranks #1 at Google, it must be the best advice around!" fit this category quite well.

Level 2: Learning
These are the folks you see attending their first SES show, posting and reading at the SEO forums and generally taking a deeper stab at the world of search marketing. Some of these people have even bought AdWords or Yahoo! Search Marketing ads, but haven't played with it much.

Level 3: Novice
If you've read the beginner's guide, you're automatically at this level (maybe even level 4 if you paid close attention). These people know basics like clean URLs, internal linking and title tags are critical to rankings. They also have a basic understanding that links influence rank, though they may still be stuck on PageRank in the toolbar as a metric.

Level 4: SEO Newbie
At level 4, you gain the title of "SEO" - you know why the meta description tag matters, why some links are better than others and how to create a search-friendly site from the ground up. You may even have a few tricks up your sleeve and have some deeper knowledge about a particular niche  - where the good links come from, why certain sites rank where they do, etc.

Level 5: SEO Professional
At level 5, you know enough to provide professional help to others. 301 re-directs are a new best friend and you've done link building work to a degree that makes you competent in nearly any niche. Keyword research is now a basic task and fixing up search-unfriendly features like select boxes and multiple URL parameters is old hat.

Level 6: Master SEO
Sixes are in a unique club. Chances are that to have this much knowledge, you read 10-20 SEO blogs each day. You're so plugged in to the search world that you've got a fair idea of what Google's last update affected in the algo and what types of spam are still effective at each engine. You're a whiz at diagnosing penalties, finding solutions to difficult search problems and quickly dominating the SERPs in less competitive sectors.

Level 7: Dark Lord of Search
I would assign this level to a select few in the world of SEO. At this level, you're often someone who's well-known in the SEO community - you might run a blog or simply be a "big time" name in the field, regularly speaking at conferences and getting pegged by Fortune 500 brands to provide insight. These guys & gals know exactly where to place links or create pages to help overrun a negative piece of press and have the connections to make nearly any type of campaign possible, assuming the motivation & money exists.

Level 8: Johns, Naylor, Boser & Ballie
I've only met four people I'd put at level 8 - Ammon Johns, Dave Naylor, Greg Boser & Jake Baillie. These guys know not only search, but coding, marketing & business like the back of their hand. Show them a problem and they'll come up with a solution that solves ten issues you didn't even know you had. Show them a sector and chances are they've optimized at least a few sites to top rankings in it (assuming it's profitable). From spam to technical analysis to scraping, re-direction, content strategies and analytics, they are nothing less than the very best our field has to offer.

So, where do you rank yourself?

p.s. I would say that a ranking chart like this isn't as relevant in our field as in others, as great levels of specialization in a particular sector must be weighed against the brilliant generalists, but it makes for a fun post, eh?

p.p.s. Had to amend this post to add DaveN - not sure how I could have forgot about him, as he's clearly a level 8. BTW - There may be many more folks who are Level 8, but I haven't personally gotten to witness it in action - my list is not meant to be comprehensive, or exclusive, just based on my own personal experiences.