Dial the 1-866 number to vote for your favorite American Idol contestant. The number is shown on the screen while the contestant is singing, at the end of her performance as she is standing next to Ryan Seacrest and again at the end of the show. If you get a busy signal, keep trying.
Use your cell phone to text message the vote. The number to send a text message is also shown on the screen while the contestant is singing, after his performance and at the end of the show. The advantage to using this method is there is no risk of busy signals.
Place calls to the 1-866 number through Skype. If don't have a landline phone and don't want to use your cell phone minutes, Skype is a good option. Go to Skype's homepage to download the program, and, when you're all set up with an account, click on the "Call Phone" or "Dial" tab, enter the 1-866 number, and hit the green phone button to place the call.
Download Dialidol and use it to make phone calls. Dialidol is a program for your computer that can dial the number to vote for your favorite Idol contestant over and over, so you don't have to tire your fingers dialing on a regular phone. Dialidol requires having a telephone modem in addition to your cable or DSL internet connection.