I can't tell you how many times I find myself in a house where multiple faucets drip when turned on and the base of toilet leaks when flushed. Often the leaks surface over night. While these two different problems may not appear to be related they are tell tale signs (along with the tan) that the owner has been away for some time.
How is a vacation related to plumbing leaks, you ask? Well, what happens is that the rubber seals or gaskets dry up when they are not getting regular use. Once the rubber has dried it can harden or become mis-shaped. When the fixture is used again the seal will not be quite water tight, which allows water to leak.
What this means is that one of the best things you can do for your plumbing is to use it. This includes all of your plumbing fixtures like those in a spare bathroom, guest house, or basement. To keep things working flush the toilet and run water in the shower and sink about once a week. This simple chore can save your plumbing in the long run.