I find it easier to read on my iPod touch than my computer screen, so I have been looking for a downloader that works for the sites I most frequently use that also works on a Mac.
Well, I wasn't successful in my search for a downloader, but I did discover a solution to my problem. I know I can't be the only person who prefers to read from an ereader so I figured I would share.
Firefox has an addon called Scrapbook. Using scrapbook, you can capture webpages, combine them, and save them on your computer. Once I do that, I use Caliber to convert the file to epub and download into Stanza on my iPod. I have found that this works for stories hosted on AwesomeDude, IOMfAtS, Codey's World and CRVBOY. I have not been able to get it to work for Nifty or The Mustard Jar.
It took a little time to figure out the best way to use Scrapbook so the stories appear the way I want them to on my iPod, but it's completely worth the effort. I can provide further instructions if anyone is interested.
If anyone knows something that works on Nifty or FictionPress, please let me know.