How can you make these dots in Photoshop?

[B u r l]

I'm doing 1 colour designs that will be printed onto a t-shirt. I'd like the image to be shaded in but I'm limited to 1 solid colour. I thought dots could work in a similar way to crosshatching does, and was wondering if there's a way I can get these dot effects in Photoshop?

[Aly Fell]

Filter / sketch / halftone? Maybe...

[papageo]

This page has a simple tutorial on making photoshop halftones for screenprinting. This is the way I used to do it when I was in that business.

The tute talks explains the process for 4-color seps, but 1 color is the same, just one step.

[TinyBird]

Kinda necroing this thread, but this is also a pretty neat and quick way to make screentones in Photoshop (and I have found this to produce bit clearer dots in large images than Filter / sketch / halftone, possibly because I just suck and can't make it work), however this works only on Grayscale mode, using this in RBG can be... trippy.

[iambanana]

I have also been looking for this. Thanks so much everyone!

[OmenSpirits]

I picked up those manga how-to books with the CD with the program that did the same thing. Plus speed lines. Very handy.