Coupons - used or not used?

Is there a way to tell if a customer has used a coupon?  I can't seem to find anything in the admin and, even when a coupon has been used, I have to manually go in and remove it.  It would be great if there was a column that automatically is checked showing that the coupon has been used (at least for those individual "one use" coupons).

You can get sales reports that include coupon code information, or that are limited to a certain coupon. However, this is currently no way to do so at the customer level. This is the kind of thing that a Certified ProductCart Developer might be able to custom code for you.