I don't think there is a dashed-line tool, but depending on the application, you could just use text and transform it according to the size you need...

no.
you have to you illustrator for something like that.

not with paths or the line tool.

cheat i thought of: text tool w/ dashes.

Or you can make a 8 X 2 pixel document, get a square brush, hit d for default colors, paint in one side of the document (4 X 2 pixels), select all, then go to Edit->Define brush. Name it "dashed" and then when you have a marquee or path you want dashed, right click and stroke with your dashed brush. You'll want to have your brush already picked before you do the right click > stroke (with brush) thing -- otherwise, it'll stroke with whatever brush you were last using.

Hope that helps.

well sort of. you can set the brush spacing so that it is a series of dots which looks very close to dashed lines. Select the brush and in the brushes folder click on the Brush Tip Shapes and that will allow you to control the dot spacing and size and shape.

Yeah, now that I just tried what I posted up there -- it's not as snazzy a solution as it sounds like it should be. Illustrator is much easier.