Today is SysAdmin Day. What, you do not know about SysAdmin Day?
SysAdmin Day is celebrated once a year on the last Friday for July. There is even a web site which advocates this celebration and provides some nifty gift ideas for them.
So go find your sysadmin and let them know how much you appreciate them with a great big hug. :-)
Note: Also take a look at Sysadmin of the Year.