You probably won't have enough play to cut and repair, so you might try glueing in a 1/4" long plastic screw, as this post mentions:

http://www.bobvila.com/BBS/Small_nail_hole_in_PVC-Plumbing-1-F6280.html

The drywall will have to be cut enough to really diagnose the problem and perhaps additional cutting will be necessary for repair access. So cut the drywall first.

well this is not a normally accepted approach but I've found it to be true. That PVC glue actually melts the pipe and fittings together, so well you can barely tell two pieces existed if you cross cut a fitting. So I once had the bright idea to repair a problem similar to this buy cutting a small piece of pipe to cover over the hole and glue it over the damaged pipe, and hold it in place with some tape, guess what.....it worked!(and this was on pressured pipe). It was temporary, but I bet it would have held forever.

next best option I'd say is to look for a slip fix coupling in your pipe size( if they make them that big), very pricey, but work great.

Cut out the drywall and determine the type of pipe, size of the hole and location of the hole.

It may be simple to do a proper fix -- cut out the damaged section and replace.

If not, consider some of the patches. The PVC glue fix is not a bad idea -- I would use primer also.

Solder could work on copper pipe and a small hole.

The epoxy putty is also great stuff -- I would sand the site with rough sand paper first.

Silicone sealant will also work wonders -- again I would rough up the area with sandpaper.

I would generally avoid bubble gum and bailing wire -- too low tech.

Thank you all for your valuable input. This morning I used a Rotozip to cut out a drywall spot that's a little larger than my thumb. Oddly enough, there's insulation in there. (I guess to block the sounds from the other side of our ZLL home.)

Upon moving the insulation aside with my finger, I could see a bizarre shape for black PVC. A little more poking revealed that this is the one of those "directional T's" that throws water in the correct direction of flow. The "T" is mounted horizontally so it forms a "T" when looked at from below.

If the previous owner had moved the hook 1cm away from the wall or cabinet, no damage would have been done. Bah!!! Instead, the hook penetrated right where the junction of the "T" is curved from one side. My head is going to rotate.

I'll try a combination of the points mentioned above. Roughing up the edges before using any kind of primer or cement to give it something to adhere to, possibly shoving a plastic screw with cement in the hole once I get it to the proper size, etc. If this had happened on an ordinary section of straight pipe, it wouldn't be so bad. But this had to be in the narrow armpit of the "T". Too bad I through away the hook that used to be in there. ;-)

Black? Hard or rubbery? If hard, no doubt it is ABS- different from PVC.

Definitely black and hard. ABS plastic, I'm certain. Glad you brought that up!

My approach (although the others sound good too):

Drill and tap the ABS and drive a short, glue-covered screw into it. i'm assuming you can do that with ABS -anybody know any reason you could not?

Good luck.

I showed this problem to a plumber and asked his opinion. He basically agreed with what was said in this thread. The screw should be a temporary fix. The difference was that he suggested using a very short lag screw with deep threads wrapped in teflon tape. Since there isn't such a thing as an ABS screw (that I know of), Teflon tape sounds logical for different materials.

I may actually do the 'screw' method and leave the small hole open to keep an eye on it. Then when we are able to have the kitchen ceiling renovated, we can take that opportunity to do a permanent replacement.

Use a self taping sheet metal screw.

If you haven't done this yet, use a stainless steel screw and it will be a permanent fix.

File the tip off of the end of the screw- no need to have something sticking out there for "stuff" to hang up on.

This is fun! Could one of you guys hand me a beer?

:-)M