Does VACUUM ever free up any disk space?

I've read a lot where people recommend using VACUUM FULL
to free up disk space, especially after many updates/inserts.

But does a regular VACUUM (or VACUUM ANALYSE) ever free up
any space?

24/7 production databases cannot be locked for long periods
of time to run VACUUM FULL, but I do not want data files
growing indefinitely (any more than they need to) so I hope
the routine VACCUM ANALYSE will take care of this.

My pg is version 7.2.x but the question can apply to newer
versions as well if the functionality has changed.

Regards,
Chris.

--
Chris Miles
http://chrismiles.info/