Sorry JCA - that's not true
http://en.wikipedia.org/wiki/At_batIn baseball, an at bat (AB) or time at bat is used to calculate certain statistics, including batting average, on base percentage, and slugging percentage. It is a more restricted definition of a plate appearance. A batter starts with an at bat every time he faces a pitcher; however, the batter doesn't get an "at bat" in the following circumstances:
He receives a base on balls (BB).[1]
He is hit by a pitch (HBP).
He hits a sacrifice fly or a sacrifice hit (also known as sacrifice bunt).
He is awarded first base due to interference or obstruction, usually by the catcher.
The inning ends while he is still at bat (due to the third out being made by a runner caught stealing, for example). In this case, the batter will come to bat again in the next inning, though he now has no balls or strikes on him.
He is replaced by another hitter before his at bat is completed (unless he is replaced with two strikes and his replacement completes a strikeout).
walks and sacrifice flies and I think HBPs count as plate appearance. Sacrifice bunts do not.