cross tab (pivtor table) sql

Hi all, I wonder if someone can help me write a sql query for the
following scenario:
I have a table that looks like the fillowing:
[time] [stock] [price]
11111   MSFT    1
11112   ORCL    2
11112   SUNW    3
11112   SUNW    2
11113   ORCL    5
11114   MSFT    4
11115   ORCL    3
etc.

I need to convert the above table to the following:
[time] [MSFT] [ORCL] [SUNW] ...
11111    1      3      1
11112    2      3      3 <-------|
11113    3      4      2 <-------|----these values are prices
11114    5      2      3 <-------|
11115    4      1      8

(obviously, don't pay any attention to the actual numbers I used).

Essentially I want to pivot my table (like in Excel or OLAP tools).
I can't use excel because I have too much data...I'd like to take care
of this in a database any way.

I tried the following using postgresql:
select time,
CASE WHEN stock='A' THEN max(price) ELSE sum(0) END AS A,
CASE WHEN stock='AA' THEN max(price) ELSE sum(0) END AS AA,
CASE WHEN stock='AACB' THEN max(price) ELSE sum(0) END AS AACB,
CASE WHEN stock='AAGI' THEN max(price) ELSE sum(0) END AS AAGI
...
from mytable
group by time, stock

(notice I had to use max(price) because there me be more than one
price update during a second).

Unfortunately this doesn't work, it just returns a bunch of zeroes. 
It seems to me that there has to be a way of doing this without
resorting to expensive olap tools.  Any ideas will be appreciated,
thanks.