Interactive websites

I have recently started using facebook. This is a very cool interactive website. I automatically get info from and about my friends as well as am able send info to all of my friends at once. Also, I like going on car manufacturer websites and building my dream car with thier "build your own" option. Very cool. It seems that just about all websites of big companies and a few small ones are all interactive in some way now. Whether it requesting information or giving it.