One of many IDL applications I have recently been working on is ASMOOTH, an adaptive smoothing algorithm for imaging data.
See ASMOOTH at work: this is Chandra's first light image of the supernova remnant Cassiopeia-A,  before and after adaptive smoothing:
 

	Original (raw) image
	Adaptively smoothed image;  all features are significant at   the greater than 3 sigma level
	Adaptively smoothed image;   all features are significant at    the greater than 95%   confidence level.  (note how the lower significance  level brings out more detail;   however,  the smoothed image  now also contains residual shot  noise)