From the Toys Section:

Amazon.com offers Parallels Desktop 5 for Mac for $39.99. A $20 mail-in rebate (included in the box) drops it to $19.99. With free shipping, that ties our June mention and is the lowest total price we’ve seen for this version of Parallels Desktop. (It’s a current price low by $14.) It enables users to run Windows on an Intel-based Mac without rebooting. Rebate expires September 30.