Live Chat can be good for some things, though it really isn't appropriate for everything. Live Chat is part of the "premium" support package that includes phone call-back service (a $9.95 per month "add-on" service to the basic hosting plan).
It is also always available to PS account holders.
From from time to time we make it available to all, but to have it always available, you need to have that premium support service provisioned to your account.
--DreamHost Tech Support