Well, I gave in... and delved into the world of log cabin knitting. So far, it's been interesting enough that I set aside my other projects and start at least two log cabin projects: an acrylic placemat and a cotton bathroom rug. I have yet to finish either of them though :-)
But I have my charity squares on needles, since they're so easy to bring along with me in transit, and i have figured out that one ball of 15-gram worsted acrylic produces a six-by-six square, but I get stumped when I encounter a knot, which is getting a bit too frequent for comfort. I tend to cut out the knot and restart the yarn, meaning I'll most likely not reach the six-inch size I want... more likely, I'd get a square of five or even four inches only.
I also have a few blanket squares done, in cotton... not enough to sew together though.