@croydon - I guess it all depends on what the person wants to do with it. I don't really like the look of a rockery, and I'd rather use my small backyard for vegetables and herbs. It's amazing what you can actually fit into a small space if you do some research and tend it carefully.
I also have quite a few fruit trees in pots (because we move a lot and I don't want to lose them if I have to move again).
The only thing that I've found difficult to fit into the space is the composting bin, but I've got a miniature one that works in the kitchen.
I didn't really use any special plants, either, I just decided what I wanted and then figured out a way to make it all fit. I'm quite proud of my vegetable garden design as well.