Looking back over the past year the chart shows a drop in price after each dividend payment that exceeds the 44 cents of the dividend. In fact the October 5th dividend seems to have triggered a drop from $38 to $33. Presumably these drops are the result of the forecast made at the time the dividend is paid. Monday will be another dividend; can we expect another drop?
Yes, when teh Ex-dividend date hits, the stock opens down the dividend (45 cents for ATT). Your cost basis on teh stock (what you originally paid per share) is tehn reduced by the dividend amount as well so that if you paid $33 per share, your basis is now $32.55 per share. No free lunch, I'm afraid.
Here is the chart. http://finance.yahoo.com/echarts?s=T#symbol=t;range=1y;compare=;indicator=dividend+bollinger+sma%28200,20%29+volume+stochasticslow+rsi;charttype=candlestick;crosshair=on;ohlcvalues=1;logscale=off;source=undefined;