My opinion is Google is a buy at current levels, but that it might be possible to 'wait' and get it at a better price. However, if you've been waiting to invest in Google, but the high price has stopped you, don't get too greedy - because like when Apple was trading at it's lows, it might not last. So, how do you invest in companies that are falling?
Buy in increments. If you want to invest 10,000 dollars into Google - buy in 4 2500 dollar blocks. Don't try to 'time' the market and get it in one shot. Buy at 505, 500, 495 etc. Be patient and have a plan. Good hunting!