Yes, they kind of hide that, and other things...

For some reason it's left out of 12.04LTS so needs to be added in
manually if you need it. Not too onerous and full instructions are
here:

www.liberiangeek.net/.../add-enable-screensavers-in-ubuntu-12-04-prec\
ise-pangolin/

Lots of screen savers but a couple are listed though not actually
installed so not usable.

BTW - have the final release running on a spare PC and getting to
grips with it. Does help a lot getting rid of the global menu but
Firefox still needs it disabling in its add-ons before it accepts the
change.

www.liberiangeek.net/.../disable-the-global-menu-in-ubuntu-12-04-prec\
ise-pangolin/