Padding time values from EXTRACT()

Hi.

If I use the following snippet

EXTRACT (hour FROM timestamp) || ':' || 
EXTRACT (minute FROM timestamp) 
AS this_time

I get single digit figures returned for minutes less than 10, resulting in the 
odd-looking 12:5 when I was expecting 12:05. 

Actual column value is '2009-11-18 12:05:31.030546', which I why I assumed I'd 
get the 0 in the returned value.

Is there any way to zero pad the only the values below 10 so I always get two 
character responses for the minutes?

Thanks,

Mark