I happen to like the half double crochet very much - it's not used in a lot of patterns, but I use it when I'm making something up. If you have a varigated yarn and alternate a single crochet and a half double crochet, you get a very nice effect with the colors. If you have a nicely textured yarn like Lion Brand's "Homespun"* and use the same technique, you get a nice effect with the texture. All you have to do is have an uneven amount of the foundation chain, so you are always putting the half double crochet on top of the single crochet & vice versa.
I know, nothing really earth shattering or insightful, just singling out a stitch that doesn't get used that much.