[development] URL Aliasing content types?

How can I create url alias for all nodes created as stories to a certain format. For example - node/4 beomes /post/4. Are there any existing modules to do this task? Thanks in advance. -- Expedition Post <http://feeds.feedburner.com/%7Er/ExpeditionPost/%7E6/1> <http://feedburner.google.com/fb/a/headlineanimator/install?id=tgbpi7srr7t35p73j02f72bk7k&w=1>