Unfortunately, pushing the sharpness will mean that you lose a lot of detail and end up with ugly halos around things.
If you are using Photoshop then there is a filter called "Add Noise" that will do a nice job. You can find it under Filters > Noise > Add Noise
Experiment to see whether the Uniform, Gaussian, and Monochromatic options give you the best result. I'd also suggest copying the layer before you try this out so that you can go back to the original if it all goes horribly wrong.
Sharpness...hmmm....USM and such doesn't do a good in adding noise, as the result will be very ugly.
If you want to add noise, you can try out various filter in PS, or just use high ISO setting when you shoot.
filter>texture>grain also can
thanks guys. but there are times that i'm only inspired after looking at my pictures on my computer screen.