I've written about bulk insert methods for text files in sql server 2005.
.Net 2.0 brings the SqlBulkCopy Class in System.Data.SqlClient namespace.
Speed wise it can't even compare to native sql server methods but it's usefull
if it's the only viable solution.
SqlBulkCopy.WriteToServer has 4 overloads:
SqlBulkCopy.WriteToServer (DataRow[])
Copies all rows from the supplied DataRow array to a destination table specified by the
DestinationTableName property of the SqlBulkCopy object.
SqlBulkCopy.WriteToServer (DataTable)
Copies all rows in the supplied DataTable to a destination table specified by the
DestinationTableName property of the SqlBulkCopy object.
SqlBulkCopy.WriteToServer (IDataReader)
Copies all rows in the supplied IDataReader to a destination...
I've come accross this white paper that explains how SQL Server 2005 can be used to support row- and cell-level security.
Preety interesting reading.
More here.