Is airline program to avoid security line worth it?

Security lines at the airport
Longer lines begin to develop as passengers wait to go through security at Seattle-Tacoma International Airport, Wednesday, Dec. 22, 2010, in Seattle. About 91,000 passengers are expected to fly out of Sea-Tac Wednesday, with Thursday's 97,000 expected to be the busiest travel day of the holiday season, which is also about the same number of travelers on an average summer day there.
AP Photo/Elaine Thompson

Long lines, Ziploc bags, removing your shoes -- going through airport security is certainly an unpleasant experience. Want to avoid all that? A lot of you now can.

One of the programs airline travelers can sign up for to expedite their security process at the airport receives 25,000 to 30,000 applications a month. What are the pros and cons to signing up for one of the options?