I use my computer to play online poker hence my sn. Thats how I make money with my computer Trouble is you have to be good.
You can make your own websites with affiliates, Ebay there's all kinds of things you can do to make money. Look into webmasters. Basically this refers to a person that makes a site advertising/marketing other sites etc.
the first and most effortless is camping u can make probably $1 - $3 a day camping pretty slow but if your comps on all the time then maybe worth it.
u can also make and design stuff in second life and of course once u have made it you can sell it.
second life is just like real life if u have a business plan for real life try it in second life first chances are its going to be a hell of alot cheaper and u get to see the outcome of it .... u know weather ur plan would work.