Sorry, gotta up the ante. I still use weighted fine mesh bags in a secondary or keg because they are cheap (and work), but I bought one of these lately to play around with :http://www.stainlessbrewing.com/Dry-Hopper_p_155.html
Way bigger diameter for hops to circulate and give off their goodness. Gonna report back soon on its effectiveness, but I love the design.
Edit - Seeing now that the other fits over the dip tube and hops are not stuffed within, I could see how the other might clog beer flow through to the dip tube. My comment about the diameter of mine allowing better circulation of hops is inaccurate therefore, but the design of mine appears better though. Curious to see how the other restricts the dip tube in a heavy charge of dry hops.