I just took my 3 dogs in for a checkup, and it's been 3 years since their last DHLPP vaccination (disptemper/parvo). Rather than go ahead and revaccinate, we ran a blood test for each dog to see if the antibodies for this were still adequately present from the LAST time I vaccinated them. They were, for all three dogs.
The "titer test", as it's called, cost about $54 per dog, and resulted in a report I can use if I need to board the dogs at a kennel that requires DHLPP vaccination (ie, I can show them that the dogs are still protected).
Running the titer test is more expensive than simply revaccinating, but over the years I've gotten more cautious about unnecessarily stressing the immune system by vaccinating again unless there's evidence that the dog is not protected.
My dogs don't typically hang out with other large groups of dogs (we rarely go to a dog park and they have not been boarded in years). So their risk of infection is low.
I also politely declined the dog influenza shot. If my dogs were traveling to dog shows with tons of other dogs I might choose differently, but mine are pretty protected. Which isn't to say we don't go out in public-- we do, as often as possible- but they don't hang out with a lot of other dogs we don't know.
I'm not a vet, but I have learned a LOT from an excellent publication, The Whole Dog Journal (I encourage you to subscribe-- I do, and you get an online subscription too which gives you access to all of their wonderful archives, including this very helpful article about titer tests and vaccines: http://www.whole-dog-journal.com/issues/5_12/features/5502-1.html )