Verizon Wireless today announced a data promotion that will be available to those who buy smartphones starting November 8. Customers who subscribe to a 4G smartphone data plan will receive double the amount of monthly data. For example, someone who chooses the 2GB plan for $30 per month will receive 4GB of data per month for the same $30. Verizon says the promotion is available to new and existing customers. Existing customers need only change their plan via Verizon's online account controls. For customers who want a smaller data plan, they will be able to add a 300MB plan to any Verizon Wireless smartphone or basic phone for $20 per month with a voice plan.