This year the folks at the NAB Show are offering up free access to the exhibit floor (normally $150), content theater, and opening keynote taking place April 12th through 15th. Although this doesn't grant you admittance to all of the main conference sessions, it's a cool deal. Just register here and use the code A913. If you want to get a sense of what the NAB Show is all about, take a look at this video of the 2009 event that was created by students.
By the way, if you plan to attend this year's BEA conference (April 15th -17th), admission to the NAB Show is included with your registration.