Ramblings from another nerd on the grid
BitLocker protection on removable drives is known as BitLocker To Go. When a BitLocker-protected removable drive is unlocked on a computer running Windows 7, the drive is automatically recognized and the user is either prompted for credentials to unlock the drive or the drive is unlocked automatically if configured to do so. Computers running Windows XP or Windows Vista do not automatically recognize that the removable drive is BitLocker-protected. With the BitLocker To Go Reader users can unlock the BitLocker-protected drives by using a password or a recovery password (also known as a recovery key) and gain read-only access to their data.
Go get it @ http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=64851943-78c9-4cd4-8e8d-f551f06f6b3d
When I tested BitLocker To Go, I could read my drive in XP with application that was installed on my USB drive when I encrypted it. I didn't needed to install any other application.
It would be more helpful to have an XP version that would allow writing to the USB drive too....
XP is too prevelant to just go away, and this feature won't gain traction without at least read/write access on XP.
My 2 cents.