Turning off services is, in reality, a waste of time. The amount of memory you'll get back is miniscule. If a service is not needed then it'll go idle and uses a tiny, tiny, tiny amount of memory, not worth worrying about.
And, as Skater notes, if you later do need those services then they'll load anyway (if you've just set them to manual) or not at all (if disabled), in which case you could then be in trouble.
Forget Black Viper, it's 2009, we don't need to worry about freeing up the odd couple of K's here and there... The OS is more than capable of handling memory availability.