The Wikipedia entry on the dollar / money dance says that it's practiced all over the world, from Poland to Mexico to Nigeria. The United States is the only country that seems to have trouble accepting this custom with open arms.
Take this entry for what it's worth. Make your decision depending on where you have the wedding and who is attending. If people are comfortable with it, it could be a great way to help the couple get started.
"Even cultures that accept this may balk at paying the groom for his time and attention, so alternatives have developed, such as "paying" the groom with play money or a stick of chewing gum. Some consider this a way for the bride and groom to have face time with their guests and to wish them luck. Some couples place a small bowl on each table for guests to leave cash or checks so that guests won't feel obligated to 'pay' for a short dance with the bride or groom, while still giving them the opportunity to spend 30–60 seconds chatting and dancing with them as the newlywed couple visits each table. Others say that the money will be for their firstborn child so the money is not for the couple.
Many, including traditional North American etiquette experts, consider the practice of asking for money from invited guests via the "Money Dance", as incorrect."