I've got the Truecrypt application installed on all our Admin machines and on staff laptops.
We're about to encrypt some USB drives with Truecrypt.

I'm aware that you can set Truecrypt to auto-mount volumes on start up which would require the stick to be inserted before the user logs on but is there a way to have Truecrypt detect and mount an encrypted USB drive when it's inserted???

I can't find anything which says you can.
If not, the way we're doing it seems to work fine. Just thought it might make things easier.