This is an oldie but a goodie.
Receptionists know how impossible it is to keep pens at their desks; their desks seem to be a free-for-all that the entire office to help themselves to whatever they want. And if someone asks to "borrow" a pen, it is likely never to come back.
So many of us do this:
It's just silk flowers, hot-glued to the top of Stik Pens, wrapped in floral tape, and stuck in a vase.
If someone asks to borrow a pen, hand them one of these. It's a cute surprise and it's highly unlikely they'll walk off with it. And even if they do walk off with it, it's easy to find it again.