I buy personalized collars from: http://www.k9collars.com/index.php
I buy the break-away collars and have our home phone number embroidered on them. Halo has had hers on for 3 years and it's not frayed yet. Pepper is on her 2nd collar because she loses them. The good thing is that since our phone number is embroidered on them, when a neighbor found the collar they called us so we went over and picked it up.