Generate a list of (days/hours) between two dates

Hi guys,

I've scoured the date/time functions in the docs as well as
google-grouped as many different combinations as I could think of to
figure this out without asking, but I'm having no luck.

I'd like to make a query that would return a list of every trunc'd
TIMESTAMPs between two dates.  For example, I'd want to get a list of
every date_trunc('hour',whatever) between 6-1-2005 and 6-10-2005 and
get a list that looks like:

6-1-2005 00:00:00
6-1-2005 01:00:00
6-1-2005 02:00:00
etc

Conversely, I want to generate a list of every day between two dates,
like:

6-1-2005 00:00:00
6-2-2005 00:00:00
6-3-2005 00:00:00

I know there's gotta be some way to do this in a SELECT function, but
I'm running into a brickwall.  I'm trying to take some of my date
handling logic out of code and use the db engine so I can spend less
time developing/maintaining code when mature date handling already
exists in a resource I've already got loaded.

Any thoughts?