I just started using this, and it already saved me a lot of time.
I couldn't find reverences to it anywere on the site, to I thought I'd bring your attention to it,

It's an OSS program that lets you create a waiting list for Rapidshare &co, and automatically downloads the files when your waiting time is over. When it can not decrypt a capcha, it prompts you to do it manually.

http://jdownloader.org/

From the site:
JDownloader is open source, platform independent and written completely in Java. It simplifies downloading files from One-Click-Hosters like Rapidshare.com or Megaupload.com - not only for users with a premium account but also for users who don't pay. It offers downloading in multiple paralell streams, captcha recognition, automatical file extraction and much more. Of course, JDownloader is absolutely free of charge.