Building on the previous answers, please note an important point, you also need to manipulate your table column to ensure it does not contain the time fragment of the datetime datatype.
Below is a small sample script demonstrating the above:
select getdate()
--2012-05-01 12:06:51.413
select cast(getdate() as date)
--2012-05-01
--we're using sysobjects for the example
create table test (id int)
select * from sysobjects where cast(crdate as date) = cast(getdate() as date)
--resultset contains only objects created today
drop table test
I hope this helps.
EDIT:
Following @dwurf comment (thanks) about the effect the above example may have on performance, I would like to suggest the following instead.
We create a date range between today at midnight (start of day) and the last millisecond of the day (SQL server count up to .997, that's why I'm reducing 3 milliseconds). In this manner we avoid manipulating the left side and avoid the performance impact.
select getdate()
--2012-05-01 12:06:51.413
select dateadd(millisecond, -3, cast(cast(getdate()+1 as date) as datetime))
--2012-05-01 23:59:59.997
select cast(getdate() as date)
--2012-05-01
create table test (id int)
select * from sysobjects where crdate between cast(getdate() as date) and dateadd(millisecond, -3, cast(cast(getdate()+1 as date) as datetime))
--resultset contains only objects created today
drop table test