I got into some surveys and after a 3 months they seen me some vouchers for shopping that my wife spent and that was cool i only make 5-6 surveys from then.
Done this just for fun.
Best way is to work in your field here and make some extra, second best is sig camp on forum, and so on.....
I have an idea for extra cash : you search if addresses on bitcointalk's profiles have clam/have been digged and you contact the members when they still have clam hoping to buy back the addresses or get a tip.
Probably not worth the time. Even if you've found an address with CLAM in it, you still have to convince the owner to give you the private key
By the way, there's a site that listed so many bitcoin address with their private key. IF you lucky you may found an address with CLAM in it. http://directory.io/