Here is another compact exercise machine that lets you work on strengthening your whole body. The Body Rhythm Dragonfly lets you target your hamstrings, triceps, biceps, quads, and abs. It has a LCD display to show your progress.
The Dragonfly ab trainer has standing, kneeling, and sitting training modes. It weighs only 15lbs, so you can move it around anywhere. It also has 4 resistance levels.