1. Pit the carriers against each other. Call each provider directly and forget the website. Get the best deal you can, then ask to speak with a supervisor. They've got more power to "make a deal" than they let on.
2. If you can hold out, try to get your service at the end (e.g., last two weeks) of the providers quarter. They are trying to meet quota and Wall Street puts as much emphasis on the change in service accounts as they do the price of the stock.
3. Try going through PalmOne. They are more inclined to give you a sweetheart deal because the longer you are on a service plan, the more royalties they receive.
4. When you've negotiated your best deal, ask them what they will give you if you sign up for two years instead of one. The discounts you'll receive are dramatic!