Faking it never worked at my house.
As for work, I usually end up having to do a lot more work if someone else calls in sick, so I hardly want to do that to someone else just on a whim.
I did once call in sick when I was supposed to be helping out at the church nursery. I was badly hung over, but told them I had one of those 24-hour stomach bugs. They didn't believe me. I didn't much care, and didn't go back for long anyhow.