Let them know you were thinking of them.
When traveling on a business trip, bring something back for your staff to enjoy. It doesn’t have to be expensive. This is one case where it really is the thought that counts. Bring home a case of apples from Washington or chocolate from Europe. This is really easy if you’re attending a convention. Just pick up a few extra-cool giveaways like T-shirts, squeezy toys or blinking ballpoint pens to share with the folks back home.
You’ll find that, in this case at least, absence really does make the heart grow fonder.