how to clean this up?

[drew_viii]

http://andrewlim.smugmug.com/photos/115235489-L.jpg

hi, ive been palying around with PS with my photos, here is the thing, i like the result, but the sky has like bits of noise or something in there, cant really seen in here i guess, but when i set it up as my wallpaper, i can really see those dirty grains on the skies, how should i fix this?

[LoveOfSelene]

Try one of these.

Either you can apply these to the whole photo itself or select the sky and apply. Your choice.

You can apply some Gaussain Blur.
Filter>Blur>Gaussain Blur Maybe a radius of 1-10

or

Try applying a Dust and Scratches filter or a Reduce Noise filter.

Filter>Noise>Dust and Scratches
Filter>Noise>Reduce Noise

Either way should work, but just don't apply too much since it will soften the photograph.