Truncate Datetime to Second (Remove Milliseconds) in T-SQL

Question

What is the best way to shorten a datetime that includes milliseconds to only have the second?

For example 2012-01-25 17:24:05.784 to 2012-01-25

Answer 1

The fastest, also language safe and deterministic

DATEADD(second, DATEDIFF(second, '20000101', getdate()), '20000101')