Determining Duration

Recently I had the need to determine the duration of a peice of code. After playing around with a few methods I came up with the below. I did a search & didn't see a lot out on the net regarding determining duration so thought I'd post this.

declare @startdt datetime,
@enddt datetime,
@diff int

set @enddt = '2009-05-12 15:27:29.560'
set @startdt = '2009-05-12 15:27:26.560'

set @diff = (datediff(s, @startdt, @enddt))

select right('00' + convert(varchar(30),@diff/3600),2) + ':' + right('00' + convert(varchar(30),(@diff%3600)/60),2) + ':' + right('00' + convert(varchar(30),@diff%60),2) as [Duration]