stock question

Any stock gurus out there?

Occassionally in a volatile market, you see a "buy" price that is significantly higher than a "sell" price -- suppose you want to sell you shares of XYZ at $5, and I want to buy them at $6. In such cases, which price is used? I believe that it is different if the stock is traded on the NYSE or Nasdaq.

Movie: "Appaloosa" looks really promising

Stars Viggo Mortensen and Ed Harris as a wandering sheriff and deputy who go from town to town in the wild west, cleaning out bad guys. The town of Appaloosa is home to bad guy Jeremy Irons. Add to this Renee Zellweger on the piano, and you've got yourself a movie, in a dirty glass. I can't wait to see it.