You may try on HYIP sector. Its not too easy to earn weekly $800!But,if you are in HYIP & you really understand the total HYIP sector, you may earn more..
i may not advice for porn at all. you can try creating niche business directories and start earning through banner ads or google adsense.
Build a website and promote your knowledge as a webcam star. Write an ebook telling others how to make money as a cam star and charge $19.95. Start up teaching others your techniques through articles and charge. Keep it clean on the website, so it does not yell porn and treat it like any other profession. Just my 2 cents worth.