the functor of p-typical witt vectors is most well known for lifting perfect fields of characteristic p into complete discrete valuation rings. however, it is a well-defined functor on arbitrary rings; we will indicate how applying this functor to local rings of mixed characteristic gives some new perspectives on p-adic hodge theory. we will also touch briefly upon some mysterious links to algebraic k-theory coming from the work of hesselholt. based on joint papers with chris davis (copenhagen).