The file format in which you record, store, and transmit your data is a primary factor in one's ability to use your data in the future. Plan for both hardware and software obsolescence.
Formats likely to be accessible in the future are:
Examples of preferred format choices:
Examples of discouraged format choices:
For further clarification:
Digital Preservation (Library of Congress) maintained by the National Digital Information Infrastructure Program, this site contains digital preservation resources, news, reports, and standards.
The California Digital Library gives a great overview on data security, storage, and backup guidelines.
Other Online Resources
Backups and Security from MIT Libraries
Guidelines from MIT Libraries
Guidelines from California Digital Library
EZID is a service that makes it simple for digital object producers (researchers and others) to obtain and manage identifiers for their objects. You can assign identifiers to anything: scientific datasets, technical reports, audio files, digital photographs, and so forth, as well as non-digital objects. This is a fee based service.