When I was leaving my dog with a dog sitter for 10 days I registered with the after hours emergency vet clinic. They take your info, the pet's info, verify your payment - all the basic info you give them when you take a pet to the vet. They also give you a tag with their number on it so if the animal is found by someone they can call the number and the vet will call you.
Monday morning my little girl Madison and I got into a ground hornet's nest. She was stung at least once and I got 6 stings. I was having chills and feeling "weird" and I assumed the poison was working on her too. I took her to the e-vet just in case. I had called ahead, told them my name, and when I got there I just said my name and they took her right in to the exam room.
After the initial exam and a shot we had to sit for half an hour to wait for reactions or whatever. While we waited I saw several unregistered pets come in, and they spent what seemed like an eternity at the check in desk whining, crying, bleeding - while the stressed out owner give the check-in information and filled out forms. I was SO glad I had registered her. If it's available near you, I recommend it.