In the forum you can get some. There are many things to do, if you are devoted to exploring the alternatives. You can start with some of them, like signature campaigns, offering goods and services, participating in giveaways and this kind of thing.
Except trading and selling services someone can only earn much bitcoins if he spends a lot of his time online doing multiple things... like signature campaigning... hunting giveaways or doing other small tasks for bitcoins...