Sprint is offering 14 WorldPerks miles for every dollar spent on a Sprint PrePaid PhoneCard. For example a 250-minute card for domestic calls would earn you 525 miles at a cost of $37.50.

The phone cards can be purchased online. A 30 minute card costs $5.40, and earns 76 miles; 60 minutes costs $10.20 and earns 143 miles; 120 minutes costs $19.20 and earns 269 miles. To place an order go online to: http://www.nwa.com/mall/offer/of_communication_Sprint_Pre-paid.html.