Was walking out to the office today when for whatever reason 787RR, the flying testbed for the Trent 1000 787 engine, was out on the tarmac doing some kind of test.  I kept hearing them asking for current temperature and altimeter setting on the radios.  But anyway, I snapped a few photos and this is one of the better ones.  Gives you an idea of just how big this engine is.

Sounds just like a turbine engine.  For whatever reason though, it didn't appear to be running.  The tail of the airplane was pointed right at my office building and the control tower and pretty darn close in proximity.  If they had the engines running it would have been pretty darn obvious.