Need some help converting MS SQL stored proc to postgres function

Hi guys, I'm in the process of migrating my database from MS SQL 2005 to
PostgreSQL and there's one final stored proc that's giving me some
problems.. Perhaps someone can give me some help? Here's the sproc:

SELECT
RecipeId, Avg(Rating) as Rating
INTO #ratings
FROM RecipeRatings GROUP BY RecipeId

UPDATE Recipes
SET Rating = #ratings.Rating FROM Recipes INNER JOIN #ratings ON
(#ratings.RecipeId = Recipes.RecipeId AND #ratings.Rating <> Recipes.Rating)

DROP TABLE #ratings

The error is:

ERROR: syntax error at or near "#"
LINE 3: INTO #ratings
^

********** Error **********

ERROR: syntax error at or near "#"
SQL state: 42601
Character: 53

Perhaps there's a different way to create temp tables? Even better is
if someone can re-write the query to not use the temp table, I'm far
from a SQL expert. Thanks!!

Mike