This is a HOWTO. How to use jdownloader to automate direct downloads, and optionally, howto use CaptchaTrader.

This is what I use to download pretty much everything listed in this forum:
http://jdownloader.org/

It automates downloading from "cyberlockers" like rapidshare, megaupload, hotfile, fileserve, etc. You can just queue up all the links and it will download them one at a time, automatically answering the captchas necessary for each file.

Let's say you want to download [NPS070] Amateur – Let Street Girls Fucking CS from here:
http://www.needjav.com/censored-jav-direct-downloads/71699-%5Bman112%5D-amateur-%96-175cm-tall-girls-visit-your-home-cs.html

You can just copy the fileserve links into your copy/paste buffer. If you have jDownloader running it will load them into the "LinkGrabber" tab. jDownloader will automatically check to see if those files are still online. Then just right click on the links in the LinkGrabber tab and select Continue. This works great for megaupload, rapidshare and handful of other sites. Unfortunately fileserve's captchas aren't automatically cracked by jDownloader. So...

One major drawback to jDownloader:
Some sites use Google's recaptcha system, like fileserve. It's not, yet, been effectively cracked by jdownloader or the likes. However there are some reasonable workarounds.
1. Type in the captchas by hand. This works fine when the download is just a few files. When you start to get into the tens or even hundreds it's ridiculous. You end up tied to your computer, waiting for each part to finish, just so you can type in the captcha for the next part. It's a huge waste of time, and can be frustrating when you mistype or miss the window of opportunity because filesonic will lock you out for 10 minutes before you can try again.

2. Ignore those sites. Try to download from sites that jdwonloader works with automagically. You'll figure that out quickly because you'll see captcha popups from sites it doesn't understand. I used to do this, but it's obviously not always feasible. Sometimes alternate sources don't exist.

3. Pay for a premium account on a given cyberlocker that you use regularly. This has it's own drawbacks, as cyberlockers go in and out of fashion. So buying more than a month or so at a time can be risky, but buying less than that can be expensive. On the other hand you get super fast download speeds, just like torrents.

4. Pay for a captcha breaking site (samples below). This has the benefit of getting your captchas cracked for you, without tying you to an individual cyberlocker. The downside is, well you're paying! And you're not even reaping the benefit of paying for a premium account because your bandwidth is still capped by the cyberlocker and you still have to wait between downloads. I have not tried these services, but I assume they integrate with jDownloader - otherwise I don't know what the point would be.
http://deathbycaptcha.com
http://decaptcher.com

5. AntiRecaptcha. A jdownloader plugin exists, for Windows only, that breaks google's recaptcha system. However it only works 14% - 24% of the time. That's not very accurate, and I was not able to get it to work at all. This is more of a cat and mouse game solution, as Google regularly updates their ReCaptcha system and AntiRecaptcha has to follow suit.
http://antirecaptcha.com/

6. Enter Captcha Trader. Captcha Trader is a way to "trade" captcha entries. The problem with downloading 100 rars for a single download is having to be at your computer, and aware at the time the captcha is loaded. Typing the captchas themselves is easy. Captcha Trader uses a trading system to allow you to "queue" your captcha entries. It works by allowing you the opportunity to break a captcha request for someone else. In exchange, someone else will break the captcha you receive when you need it. You get 7 credits for typing in a correct captcha, and it costs 10 to cash out using their jdownloader plugin. Once you create an account you get 100 credits for free, then download the jdownloader plugin and read the instructions on how to use. You can also buy captcha credits, just like option #3 (although I have never tried this), if you're too lazy to earn some. To earn more credits, just login to your account, then click on the earn credits tab. A captcha will appear and for each one you submit a correct answer for you will receive credits.

http://captchatrader.com/users/refer/wares/

I didn't see any rules about referrer links. I did see a rule about advertising, but this is not an ad. Captchatrader isn't about making money, just captcha credits. So hopefully this link is ok. Otherwise I'll edit it out. And the service, which I'm not affiliated with has just been very useful for me. If a moderator wants to edit out my referer, you can always just goto captchtrader.com directly. It's a pretty cool service - and it's all about sharing: sharing captchas.

Good luck!