shading texturez

[Dog on Fire]

I have been trying to get a nice "speckle" texture to use as shading for a design I am working on. Can't seem to create anything convincing enough though. I have been working with concrete textures and blowing the fuck out of them in photoshop to try and get the feel but it always seems forced and too digital-ish. Any advice on how to get a nice texture similar to these bad boys?

GigPosters.com - Andrew Bird - Pale Young Gentlemen
GigPosters.com - Arma Secreta - Perfect Vessels, The - Jd Reager & The Cold Blooded Three

I have a feeling the answer may be using a xerox machine but I don't know where the hell I can find one of the older ones with the right kinda toner.
Any help would be great ya'll

[Iron Canvas Studios]

you can use this as a starting point I'd say:
Making charcoal-y/stipple-y looking shading. I see it a lot on here...help!

[Dog on Fire]

Thanks Iron Canvas thats just what I was lookin for!