Saw this on Amazon and thought, "I'll link that to a friend, she might like it"
Then I saw a video (clean) of it, and cracked up laughing.
http://youtu.be/T4e8NsmAH1c
There is a dildo on a space hopper type thing - its effort, but in the comfort of your garden you get a bit of exercise whilst the neighbours think youve regressed to a youthful playtime.