I'm a crocheter and a knitter, but I tend not to join swaps (I have problems with procrastinating on things that have a deadline)

I crochet shawls and afghans for fun all the time tho. There are "official" patterns for the Prayer shawls (by the people who thought it up and publish the books) but on a lot of the crochet/knitting/yarn themed websites that I go to, people create their own prayer shawls out of just about any shawl pattern you can find. I've never made a prayer shawl, mostly because I'm atheist, but I have taken one shawl to be blessed by a priest for someone I was giving it to, because I knew the person would appreciate it.

If you want links to free crochet patterns for shawls or afghans, ask me. I know of a ton of crochet sites that have some pretty cool stuff. I also know a few people who have YouTube video demonstrations on how to do certain types of crochet/knit stitches.