What did you do last night? According to the Nielsen Company, there's a pretty good chance your answer is "watched TV." Nielsen reports that TV watching is more popular than ever among Americans -- up to an average of 151 hours a month. And we're not just watching television programming on TV, we're also tuning in on our computers and cell phones too.

Let's do the math: 151 hours a month, divided by 30 equals ... five hours a day. Ouch.

Here's the thing about TV: Unless you've got Jillian Michael's 30-Day Shred in the DVD player, chances are you're watching that boob tube in the couch potato position. And if you're like me, there just might be a bowl of chips in your lap too. Five hours of that? A person just might start to grow roots.

Experts believe that the economy is playing a role in TV's growing popularity. People are staying home and pinching pennies, so they turn to the television for cheap entertainment. Like we pointed out last week, eating right doesn't have to break your budget, and staying fit when times are tight is pretty easy too. Here are some low to no-cost ways to have fun and stay fit at the same time. Turn off that TV and give them a try.

• An indoor walk or run requires equipment, either your own or borrowed from a gym. Take your workout outside and enjoy it for free ... along with some fresh air and sunshine too. Find a local hike here.
• Reclaim the Frisbee from your dog and head to your local park. A spirited game with a friend will get that heart pumping. Or head to a local disc golf course for a little extra competition.
• Got a Wii or a Wii Fit in the house? Send out invites for a Wii party. Sure, you'll still be in front of the TV, but you won't spend much time sitting.
• Gather up all the old fitness equipment you can find and set up your own circuit workout in your back yard and basement. (Bonus benefit: Cleaning those closets count as exercise too.)
• Dust off your bike and get ready to ride. Make it fun by planning a route that that suits your interests. Go on a historical houses tour or to a local conservancy, your favorite hang-out or an outdoor concert. Pack a healthy picnic and call it a date.
  
• Go on a scavenger hunt. Geocaching and its low-tech cousin letterboxing both involve hiking in the woods, hunting for a hidden cache.

Now it's your turn -- what kind of fun and frugal fitness ideas can you share with us?