How to keep Generation Y motivated?

Nowadays there are a lot of young employees in
companys. Is it good? What are the benefits of it?
How to motivate them?
I have listened to Financial Times podcast about
Generation Y. Who are they? Generation Y is
a young population who were born in 1977 to 1994.
It is really good to employ Generation Y because
there are a lot of benefits. Generation Y is highly
enthusiastic, they can spend sleepless nights
on their work (if they are well motivated),
they have a lot of new ideas. But how to keep them
motivated? Gen Y is looking for learning opportunities
and also for career that young person can develop in.
They would like to be challenged. The company should
provide them goals and give, for example, names of
people who might help them with theirs work and the
employers might be surprised with new ideas.
However there are some disadvantages of motivating
Gen Y. As we can listen in the podcast Generation Y is
absolutely unmanagable. They might take an ideas in
different directions and just take their own decisions.