OK, I found the photos I'd done some 'digital filtering' for and posted them up for you guys. I didn't *really* process them, I was just testing out the features, so they're not 'final photos'.
Basically, you can use colored filters when you're shooting B/W to change what your image will look like. Use a red filter and reds become lighter and blues and greens become darker, etc. In Aperture there's a monochrome setting that allows you to process it as if you'd used any particular colored lens. You can also simply desaturate the image or use a 'default' monochrome setting that is similar to desaturated, but just a hair different. (It gives increasing emphasis to blue, red, then green.) Dunno about other apps, but the effect is certainly doable by adjusting the various color levels before monochromizing.
I couldn't get Aperture to give me nine columns on the web page for the variations I did, so for each image there are two rows plus an extra filler image. The order:
My pick of all, the original, desaturated, monochrome, red filter
orange filter, yellow filter, green filter, blue filter, extra image
plus a couple of extras at the bottom
Mount Tam Filters page
Now let me assemble some DoF photos I took last week...
yep, I've read that before. gotta go browse to see wheere I end tup this time
