I've added a couple of links over on the side for bloggers working on letters. They're not necessarily going to finish them up as samplers, but they are working on the samples, if you get my drift. So go visit Island Threads and Pieces from my Scrapbag. If I knew HTML I'd make it so you could just click right here and go to the sites, but I'm not that smart.
The other place to see letters in action is over at Bonnie's Quiltville Quips and Snips. Bonnie has made a couple of tops using improvisational letters.