Noise in images? No good way to get rid of it?

Sometimes I see myself confronted with this problem and the denoising filters in the Gimp just won't do the trick or result in a smudged image.
So by pure chance I recently found GREYCstoration which is an

Open source algorithm for image denoising and interpolation, using state-of-the-art image processing techniques.

It comes for the three major plattforms Windows, *nixes, Mac OS as a command line or with a GUI or as a plug-in (for the Gimp).

I must say that the results are really convincing, although so far I have not really tinkered with many of the parameters - and I have only tried out the denoising part of the algorithm which - if we believe the website and the examples shown there - can also rebuild images called "Image Inpainting", i. e. remove non-image parts such as overlaid text or even reconstruct damaged/missing pixels.
GREYCstoration is also supposed to be a great tool for resizing, esp. enlarging, images with better results and less blur than other algorithms, but I am not sure about that or if it is generally a good idea to Blow Up pictures first of all.

Having said all that it is up to you to test it for yourself if you think it can be of any use to you.