Tux On Ice

Substitute of suspend2.

From the official site:

TuxOnIce is most easily described as the Linux equivalent of Windows' hibernate functionality. It saves the contents of memory to disk and powers down. When the computer is started up again, it reloads the contents and the user can continue from where they left off. No documents need to be reloaded or applications reopened and the process is much faster than a normal shutdown and start up.

Links
http://www.gentoo.org/doc/en/power-management-guide.xml#doc_chap7

http://www.tuxonice.net/

Allowing users to hibernate
Depends of Sudo.

As user you have only to: