15 years and counting for me - not just same company, but same position. The title changes and I get promoted every couple years, but it's the same PCN doing basically the same thing.
I'm basically the technical management of a development group at a large transportation company. The technical part of my department isn't really all that bad. The challenge is knowing the business and all the weird, intricate little nuances of both our clients and how the actual business operates. I figure it takes 18 months to make a newbie a net positive in the group. I rarely hire because typically we focus on getting people who are going to stick around. It's just too costly to productivity to have short timers around. It's also how I've successfully fended off "well, can't you just outsource some of this extra work?" If I'm looking through resumes and see you only stay at similar jobs for 2-3 years, I'm not even going to read the rest of it. I assume that candidate is going to suck up all the resources to get him/her trained and then move along before they've contributed as much back. I'd much rather have someone that shows they're on the track to becoming a greybeard. You know - the guy who has been there forever to become an uberguru, and sits in the corner and says little, but when he does you should probably take it as if it were handed down on stone tablets.