Unlocking devices?

[Will McCutcheon]

Quick and (maybe) easy question.  I spend a lot of time using serial consoles on FreeBSD and for a variety of reasons am constantly ended up with serial ports that are "locked" or "in use", even when there's no program attached to them anymore (cu or minicom getting killed can reliably cause this).  I understand why this happens so I'm not complaining about it, but I wondered is there some way to force the system to free up /dev/cuaa0 without restarting?  Thanks for your help!

W