As you may know, I am a big fan of Annie's Attic and download their free pattern of the day faithfully. I wanted to drop a note to let you know that recently, they have been giving away plenty of free afghan patterns. Yesterday's pattern was a very nice "mile a minute" afghan. You can't repost any of the free crochet patterns, or even give them away to other people, but you can save them to your computer and keep them for your own personal use.
I have heard other crocheters state that Annies Attic repeats the free crochet patterns each year, but I didn't download them faithfully last year (and I also lost all of my previous files on my computer) so I am not even sure if they are repeats or not. However, I am noticing a little bit of a pattern in the way the free crochet patterns are being selected. You'll also find that they give away holiday appropriate patterns during different seasons as well.