I have bought the Seagate FreeAgent GoFlex Drive(500GB) at the Comex Show 2010 for S$99. A free pouch for the external drive was also given out at the Comex Show. This drive works on both Mac & Windows. It will allowed me to used my Time Machine on the MAC to backup my MacBook and also on my Windows 7 Laptop.
You may have some questions on how to setup the Segate GOFlex Drive on your MAC OS. This article by Seagate may answer most of your queries.
Click here to the article>>>
Time Machine is a powerful backup utility on the MAC.It will copy everything on your Mac — photos, music, videos, documents, applications, and settings. You will never have to worry about losing any of your digital files on the MAC.