I did an article last year about repairing gear in the field. They gave me all of these fancy repair kits to mess around with, and I tried other stuff too, various adhesives, string, junk like that. I wrote the article, and talked about Fastex buckles and whatnot, but the truth is, that for field repair duct tape really can't be beat.
In addition, my repair kit has a couple of Zip Ties, sandpaper, HotBond, a diaper pin, some Seine Twine, Glide Dental Floss (made by WL Gore BTW), needle, alcohol wipes, piece of really thin wire, tent pole repair sleeve, aluminum foil tape. About 4oz not counting the duct tape, which gets wrapped around a Gatorade bottle.
On a recent trip I had the lightest pack, and this repair kit got used by everyone in my party, so I guess it's got the right stuff in it.