[dole]

the bottom portion of the screen (with hard keys) is capacitive, which means it can tell where you're pressing on the bottom portion and (i believe) it's just not hardware switches right underneath the home/back/call/end "button" on the screen. so when you press the home, call or left "buttons" on the left side, it's pressing the same button and it can tell if your finger's between the home and call buttons and interprets it as a "left". if you want to press "left", you're better off staying farther away from the rim of the center button than you think (especially for palm converts). rich's pic above was the one i wanted to find and reference. interesting the "arrow" goes all the way to the sides, though, didn't know that.

check the following link, may also explain things a little bit...
http://www.engadget.com/2008/08/20/h...t-not-how-you/