I can't think of anything feasible that would hurt the players or owners financially. Anything I've thought of would seem to hurt merchants, venders, parking lot attendants, etc. more than it would hurt the owners or players.
So... I have a simple idea. Something that wouldn't really impact the pocketbooks of any of the players or owners, but would at least allow for the collective voice of fans to be heard:
When the NBA resumes, select a prime-time moment at which fans at all stadiums can be alerted via whatever web-messaging is available (I don't really know how these twitter or whatever things work) -- and fans across the country could simultaneously do something: Stand and boo; Create a chant of some sort; Be silent and hold up 'protest posters' --- whatever, and have it last 5 minutes or so to get the attention of the players/ owners, etc. It may seem a hollow gesture in the midst of fans returning to the games, but it at least allows some measure of voice/message from fans regarding a situation in which we have had no contol and have been ignored.
Thoughts?