Question: There comes a time when time-outs don't cut it anymore.

Normally, when my kids exercise poor judgement, I let them experience natural consequences. However, sometimes their actions go against what we are teaching them and the consequences are rewarding. 

When pre-teens break the rules or disobey, what consequences are appropriate?

Answer: 
It depends on the privileges they have. Sometimes, giving them extra chores is appropriate (say, if they've broken something and you want them to make restitution.) Many times, though, you'll want to take something away from them. Anything short of food, clothing, and the roof over their heads is fair game-- depending on the severity of their rule breaking.

Items:

* Cell phone
* computer
* TV
* games

Privleges:

* Playing with friends
* Being driven places
* Getting allowance

My dad always used to ask us the trick question: "What punishment do *you* think you deserve?" You can try that one if you run out of ideas ;)
Besides taking away privileges, it is really important to kids this age to express themselves as individuals. You may not always like what they choose to wear but sometimes it's tolerable. Make sure you have given them enough so that there is plenty to take away.

How they want their hair done.
A special pair of shoes.
Food they like to share with their friends.

If they like to sleep in on the weekends. Make them go to bed early and get up early in the morning. Then have them do something physical; pull weeds, lifting heave objects, etc...