The FAA has a new online database up that maps and tracks the status of Special Use Airspace; MOA
http://sua.faa.gov/You can search SUA status by nearby airport, state, route of flight, center, and display the results on a map or as a list. One note of caution, the default altitude for the map display is FL290 through FL600. That excludes a lot of SUA that might apply to our flying.
Some of the links seem to not be operational on the opening page, so you can jump directly to these locations:
This is very similar to the TFR database at http://tfr.faa.gov/tfr/list.jsp that has been online for a while now. -- GeorgeClark - 23 Nov 2006