1. Improve security
If others have access to your PC, it's easy for them to input a USB flash drive and make copies of your data. If you're using Windows XP or later, though, there's a simple way to prevent this from happening.
Go to 'HKLM\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies',
and create a DWORD value called 'WriteProtect' and set it to 1. You'll be able to read USB drives, but not write to them any more.