Just give them away as promotional or thank you gifts at conferences, trade shows, or office functions. If you're a teacher, you can have your students sign their name on a pen or pencil so that they remember you as a great teacher and person.
Customized cufflinks are a great way to advertise for your products or services. Get your company logo printed onto the cufflinks for the added benefit of branding. Or, get a few personalized cufflinks in colors that your staff will wear. Or, why don't you give your employees cufflinks that say something about the day or event that they're celebrating? Customized cufflinks are inexpensive and are sure to make a lasting impression.