Hello, I will soon be purchasing a number of laptops running Windows 7 for our mobile staff. Due to the nature of our business I will need drive encryption. Windows BitLocker seems the obvious choice, but it looks like I need to purchase either Windows 7 Enterprise or Ultimate editions to get it. Can anyone offer suggestions on the best course of action:

a) Use BitLocker, bite the bullet and pay to upgrade to Enterprise/Ultimate

b) Pay for another 3rd party drive encryption product that is cheaper (suggestions appreciated)

c) Use a free drive encryption product such as TrueCrypt

Ideally I am also interested in 'real world' experience from people who are using drive encryption software and any pitfalls to look out for.

Many thanks in advance...

UPDATE

Decided to go with TrueCrypt for the following reasons:

a) The product has a good track record

b) I am not managing a large quantity of laptops so integration with Active Directory, Management consoles etc is not a huge benefit

c) Although eks did make a good point about Evil Maid (EM) attacks, our data is not that desirable to consider it a major factor

d) The cost (free) is a big plus but not the primary motivator

The next problem I face is imaging (Acronis/Ghost/..) encrypted drives will not work unless I perform sector-by-sector imaging. That means an 80Gb encrypted partition creates an 80Gb image file :(