Once I included an identity with increment 0 in one of the questions in a set designed to discover whether job applicants had two brain cells to rub together. Does that count as using something other than (1,1), or would that be misusing? The result was rather disappointing, only about 10% said anything like "you can't do that" or "that's an invalid increment".

A couple of times I've used integer identity(-2147483648,1) for table which would have rather a lot of inserts (rather a lot of deletes too - the actual row count at any point of time would be much less than 2 billion, but the identity range needed to be that big).