Longest is a Contempo Casuals tiered black chiffon skirt from the late 80's, maybe early 90's.
Shortest in recent memory is a BR mauve sleeveless top I got from a swap right before coming to FL. Wore it once, maybe twice? Realized although it was fine it just wasn't 'me'. Had it in a donation bag within a week.
Shortest that I remember buying for myself is black shorts summer 2012 for $7 at the discount store. Rise too low, inseam too long. Tried twice, tugging and pulling both times. Gave away to a younger waitress at work after looking at them sit in the drawer for a few months.

I've loved reading all the stories here, and especially want to see pictures of IK and Ceit's gorgeous-sounding vintage clothes.

And, Biscuitsmom, that's such a mean thing to do to you. I'm sorry.

For me, owned longest is a scarf my grandparents brought back for me from Ireland or Scotland when I was in elementary school. It's a very lightweight woven wooly material in blue and purple, and I should really wear it more. Next is probably a sweatshirt with the Ben & Jerry's logo in Hebrew that my sister brought me back from a heritage-tour-type trip to Israel circa high school. I haven't worn it in ages, but my husband actually just "adopted" it to lounge around in when it's cold. I also have some jewelry I've had since I was really young, but not sure if jewelry counts.

Shortest-owned: Some random clearance thing ordered from Old Navy that didn't work on me (a short-sleeved cardigan, maybe?) that I kept in the box for a few days while deciding whether to go through the effort of returning or just donate. I then brilliantly went and tossed the box into recycling, completely forgetting there was anything still in it.

Oldest: I have a black clutch bag with a pearl closure that was my mother's, circa 1950's. I also have a hand-knit sweater made by my mom, probably from the same era, but I'm not sure. The oldest thing that I wear every day is my mother's wedding ring, a second set that my father gave her in the 1960's. Although not the oldest thing, my mother was almost finished knitting me a scarf when she passed away in 1984 - my aunt finished it and I have worn it every winter since.
Shortest owned: A $20 pair of Spanx pantyhose that I put a hole in while putting them on. Don't you hate when that happens?

A traditional Norwegian sweater that I begged my mother to buy in Wisconsin when I was in college in the early 90's. I was A-ha obsessed in junior high and high school.
Can't think of the shortest item.

Longest: a top I crocheted myself in high school, in the late '70s.

Shortest: not sure, probably an online purchase top that wan't right but that I didn't return (and passed on quickly).

Shortest: returns, items on the way, etc.
Longest: I too have some baby clothes that are now doll clothes, but longest worn (currently) would be 2 tops & a skirt from 15-16 yrs.