I was a little bit skeptical as I cut the browning root end off while making a salad, but I went ahead and potted it up and put it at the window. This is it after just a couple of days!
To see if anything was happening underneath the plant, I picked it up (scientific investigation, don't you know). No actual roots yet, but there does look to be some callousing and a row of pre-root bumps starting to appear. I'm hopeful I'll actually have plants growing soon, but even if not, there's almost enough leaves to put on a sandwich now. I feel so frugal. Talk about not wasting anything!
I used organic lettuce from Absolute Organics. Fresh organic fruits and vegetables delivered to your door is a wonderful thing. It's convenient and quite reasonably priced. If you're in the Charlotte area, I highly recommend them. This sounds like an ad, but it isn't; I really just love the service. We eat more veggies because of it.