One technical indicator worth watching is the number of stocks trading above their 50-day moving average. This is not a perfect timing indicator, but it does provide some insight into how broad based the market advance has been since August.
As noted in the first chart below, over 80% of the stocks in the S&P 500 are trading above their 50-day moving average. On a standalone basis this indicator would not be a sufficient reason to eliminate equity exposure. As the second chart of the S&P 500 Index details, stocks ran for an extended period of time (September to December 2006) even though a large percentage of S&P stocks were above their 50-day MA.
Data for other indices can be viewed at stockcharts.com. The moving average indicator for the NYSE is $NYA50R and for the Nasdaq the indicator is $NAA50R.