Vinegar, a "new fad" in cleaning.

My friend had a party this weekend.  She decided that before the party, she was going to clean her carpets with a vacuum-like shampooer.  Her other friend suggested using a water/vinegar solution.  She put 1/2 cup of vinegar into the water basin of the machine and filled the rest with water.  When she began shampooing, she noticed immediately how much dirt was being pulled up.  (For the record, she is an overachiever in my book!  She claims she shampoos her carpets two times a year.  My 8 year old was 6 months the last time we did that!!!)  She figured that it was a different machine she was using and that is why it was pulling up so much dirt.  She had to change the water solution 5 times.  When she mentioned to her friend about how much dirt was being pulled up, the friend assured her that it was just a great cleaning solution and was easier to see all the dirt coming up, whereas store-bought soaps had suds and made seeing the dirt coming up almost impossible.

Another benefit?  I came over to help her get the food ready and I didn't notice a sour vinegar smell at all!  In fact, I had to ask her if she had cleaned her carpets yet...

I am intrigued.  I think I might try this "fad" of using vinegar to clean things.  I might decide to break out the giant shampooer and use up some of the vinegar in my cupboards.  

-Is all vinegar created equal in cleaning?  I may need to do a little more research.

-How often should your carpets be shampooed?

-If vinegar works, does that mean I don't get new carpet in our livingroom???