I've been monitoring the chart of the Dollar Index (DXY for short). The dollar spent the last few months rallying off its low. But in the past several days, it's been losing ground and it's dangerously close to a major breakdown. The greenback is trading through one support line (in cyan) today, and if the second one goes, this dollar selling could really get nasty.
One other thing I'll note: The DXY chart and the chart of the HGX (Housing Index) look awful similar since roughly the beginning of 2005. Does that reflect the international currency market's judgment that "as housing goes, so goes the U.S. economy?" I don't know. But it's worth noting the apparent correlation.