It definitely is a good idea, especially in these economic times!
Teaching kids to budget and keep a record of their spendings may sound too complicated to do, but it really is necessary. It would teach them about cutting out unnecessary spending, and give them healthy saving habits.
You could get them a small notebook, and tell them that they should record every time they spend money (even if it's on something small like candy) in the book. If they get allowances or have a small job, tell them to work out how much money they get per week, how much they normally spend, and what is left over. You could then teach them how to cut out the unnecessary spending, and that the money that they save can be used for something really big, like something they really want, or for a future trip/event, or even college.