My little sister (19) just got a 2000 Limited 4x4. 55,000 miles $18,000, oh and just to make you guys mad, it has the rear locker, and she'll never use it...
Sorry no pics, but is that off-white/silverish color.
My mom has had her Limited for 6 years and has yet to touch the locker either but I make sure it still works by truning it on about every 6 months or so.
A factory locker locks the rear axle when engaged so you get equal power to both wheels vs. just one wheel.
Toyota had factory e-lockers as an option in the 3rd gens. I'm not sure the year it started but it ended when Toyota introduced ATRAC if I'm not mistaken (2001 or 2002).