We plan to develop a user-level library for a new model of location-transparent storage. This may be viewed as an extension to existing user-level parallel I/O libraries that not only stripes files, but maintains read-only replicas of records and information about access times. Therefore, a read access to a record may be redirected to the most appropriate location. Unlike a cache, where there is a strict hierarchy of access times (that usually differ by an order of magnitude or more), access times to local disk or network storage change based on load and network conditions, and may not even retain a strict ordering. Critical to the operation of this library is development of a dynamic runtime performance model that can provide performance data of the execution environment on-the-fly to calculate access costs. This is a first step towards a more ambitious plan to support dynamic relocation of code as well as data.