I used to do a km of swimming - mostly freestye but some breaststroke - and then another km of just kickboarding. Would then finish off with walking a few laps from the shallow end of the lap pool until the water got to say mid torso. Not the best exercise for weight loss because you're not supporting all your own weight, but the best thing I've ever found for all over toning.

Its the one thing I regret about our move to this house - there is no decent 50m pool anywhere less than 30minutes drive away. I miss swimming so much - found that not only was it great for toning and fitness, but I loved the mental release I got of just swimming lap after lap in peace and quiet.