Here's an interesting, and easy, variation of single crochet stitch. It's called a spike stitch, otherwise known as long single crochet stitch. You can see the spike stitches in green; they're the longest stitches you see pictured. The other stitches shown are all ordinary single crochet stitches.
Want to learn how to crochet this stitch? If so, click the photo at right and you'll be magically transported to the step-by-step tutorial.