Okay ... it's pouring outside. You can't even see the road, let alone run on it. That's no excuse not to run at all. Get a mini trampoline. These are inexpensive, don't take up much space and can give your an amazing workout. I'll let Betty show you some moves:

Mini Trampoline Jogging
Put on some music or place the trampoline in front of the TV. Stand on the trampoline and alternate lifting your feet off - joggin lightly on the spot. Keep this up until you start feeling warmer.

Mini Trampoline Sprinting
Now lift your knees a little higher with each step. You can also alternate curling your arms at the same time. Try to keep this up for about 2 minutes. Then go back to light jogging for 1 minute. Alternate between these two moves for 10 to 15 minutes. As you get fitter you can try do the sprinting for longer, using the jogging as a warm-up and cool-down.