Microsoft introduced database snapshots with SQL Server 2005. A database snapshot is a static, read-only copy of a source database that gives you a consistent view of a database as of a certain point in time. You can use the snapshot for operations supported by a read-only database, such as reporting applications. You can create multiple database snapshots on a source database. You can recover the source database to the point when the snapshot was created from a database snapshot. However, when recovering from a snapshot, the source database must be available.
Database snapshots are available only in the Enterprise Edition of Microsoft SQL Server 2005 and all recovery models support database snapshots.
Check out my article on SQLServerCentral.com that explains hows exactly this feature works, why you may or may not consider using it, and how to get started using it.