As tempted as I am I think I'll refrain from joining the rest of the above in spamming affiliate links for my own benefit, because nobody will click those anyway
The best way to make money online without a massive initial investment is to find a good affiliate network and then look for a handful of products, after you find products that you feel you would buy yourself, find ways to sell it to other people. Webhosting, autoresponders, etc. are all relatively cheap these days, for all my sites (not including advertising), my overhead only runs around $400 a year.