Playing online casino games is a good way to make some serious money if you know what you are doing. I know several people who happily make a regular income from playing online casino games and poker games from sites like Golden Tiger – Play casino for free.
Be careful though, if you want to do something like this I would suggest joining a site that allows you to play for free (like the one I just mentioned above) as that way you can play the games, learn your craft and not have to spend a heap of money in the process.
The site also has some good incentives to sign up such as free money to get you started and also special tournaments. I believe they even offer to add a little extra everytime you deposit some money with them.