I don't know if any of you guys have tried it or not, but there's a Guitar Tricks tuner on the site that can be downloaded to your desktop.
It plays notes that you have to match by ear, instead of a needle and lights but I've actually found it to be a really fast way to tune up my acoustic just before recording. Plus it's got several alternate tunings as well.

Just download it and leave it on your desktop. Double click on the icon when you want to use it and hit the keypad numbers 1 thru 6 to trigger the sounds.
You just listen to it real quick to make sure everything's in tune, then switch back to your recording software.