I use time-outs with all three of my toddlers, and I think they're effective in the short-term. We have the time-out corner, which is in the living room between a bookcase and a wall, and they have to stand in it, facing the wall. It's for those impulsive moments: whacking one of the other children, stealing toys, (gah!) biting...
My house is so fun.
My little ones are 2, 3, and 4. Time-outs last just a couple of minutes, after which the child must apologize to the one he/she hurt. They understand it, and will even place themselves in the corner if they know I'm going to put them there anyway. That's really cute.
For my older child, we use loss of priveleges. PS2, playtime with his buds, television, computer. We're having trouble with him remembering his assignments from school, so he's on a stepped-loss program.
We also use a reward program. I have a chart, with things like 'picking up toys', 'putting clothes in the laundry basket', 'no fighting', 'keep food in the kitchen', just a list of things we've had problems with. The kids earn a point every time they accomplish something on the chart, and when they get ten points, they can choose something out of the Reward Box. I stock it from the Dollar Store. I also have things on there specifically for the older child (Cleaning his room, for one), and he can choose whether to pick from the box or earn cash.
For medications, there's so many good-tasting ones on the market that it hasn't been a problem. One time, though, one of the little ones was put on Prednisone and another yucky prescription (I can't remember which!). He would not take it, and after taking a taste myself, I understood why. Blech! So I called the pharmacist, and he advised me that one of them could be disguised in grape kool-aid (worked!) and the other med went well with chocolate syrup. I don't know a kid who wouldn't take a spoonful of chocolate syrup. So when in doubt, call the pharmacy. They have tricks they'll share.
Potty training has been difficult. My youngest is just starting, we bought his first underpants last week. Here's a little anecdote for you: When my now-4-yo was training, he was outside with his father. He had to potty. Dumb Daddy decided that instead of bringing him inside, he'd show him how to use the Great Outdoors. Dear Son took that as an invitation to potty everywhere, and he did. The living room, the hallway, the front yard, you name it. If he had to pee, he just pulled down his pants and went. It took me a long time to undo the damage. Not to mention all the carpet cleaning. My daughter was easier. She trained at two, while I haven't been able to get the boys fully trained until three. One thing I think is important is to make potty training fun. It demands positive reinforcement. My husband would get upset if one of them had an accident, and if he yelled at them, I was put days, even weeks behind on what we'd accomplished. Be patient, and be forgiving of the inevitable accidents. And keep impatient husbands out of the room!