Go to Image -> Image Size. Uncheck Resample Image. Enter 300 as the resolution. Voila. Mind you, the print size is going to go down, while the pixel size is going to stay the same. BUT! The resolution depends on where you print it. Maybe you need just 250 dpi or something. Ask. Drac, if you noticed, when you go to Render to disk and change the resolution, the inch dimensions fall down fourfold. So you have to enter the resolution and then inch dimensions to get what you want. Basically, what Bryce does is applying that thing from Photoshop during render. So, gd, if you want to render for print, just think of dimensions, multiply by 300 and you'll get pixel size. (frex, 20x15" times 300 equals 6000 x 4500 pixels) Then divide by four and you'll get the size of the document (1500 x 1125) needed to render at four times size onscreen. Or you can always render to disk. Er, am I making myself clear? PS ASK about resolution and dimensions at the place where you will have your images printed.

-- erlik