How long did your U.S. green card take?

The U.S. green card process seems to take an astonishingly long time (assuming you aren't taking advantage of corrupt government employees). A feeling of lock-in with your current job adds to the frustration, because quitting can jeopardize or reset a permanent residency application that has been going on for months.

U.S. immigrants, how long did your card take? Did it seem to benefit from theoretically-irrelevant factors like which company you worked for? And, does it seem like the high tech industry is any faster for acquiring a green card (compared to, say, these people who seem to get cards after crossing the border under questionable circumstances)?