Everyone is an expert on something — typically. We all have things we are
obsessed passionate about. For example, I’m passionate about web technology, web services, web start-ups, and music.
It’d be great to have a profile that stated what you were an expert in, a novice, etc. People in various online communities could add to your rating. Similar to how Google’s PageRank system works in that the more links from reputable sources, the higher your PageRank is — this system could work similar. If 5,000 people declared me as an expert — that might not count as much as 5 people that had 5,000 people declare each of them as an expert on the subject that those 5 are declaring me as an expert on.
Update: I’m thinking this for everything — whether you’re an expert in not cooking in general, but niche’s like “Italian Cooking”, NASCAR statistics, Big Ten College Football, Current Political Issues (Democrat views), BMX Bike Building, etc.