The start of a new solar cycle is almost always indicated by the appearance of a 'high latitude' (> 25 degrees) sunspot which has a magnetic polarity opposite of the majority being observed in the current cycle. Solar scientists at NASA's Marshall Space Flight Center and NOAA's Space Weather Prediction Center are extremely interested in a new plage region which rotated into view a couple days ago. It almost meets the criteria -- only no spots have yet formed. The current solar minimum is predicted for March 2008, but that may soon change if spots develop in this region over the next couple weeks. The sunspot cycle was first noted by an amateur astronomer, Heinrich Schwabe, in 1843.
Update -- the plage region mentioned above did not form any sunspots; I guess we have to wait a while yet... VR
