Thanks. Actually, I don't use PhotoShop, and sometimes I use Paintshop Pro 5 for lighter work. Like this, in fact--all these color images were created in PSP5.

The extra step of averaging IR+G or G+V is simple. Select Arithmetic from the Image menu (assuming PSP8 menus are laid out similarly to PSP5). In the dialog, select the two source images (tip: The long filenames overflow the list and you can't read the crucial filter character; I change the filenames to generic "IR" and "V"). The function is "average", the channels should be red (uh, remember to have previously converted the images to grey scale), uncheck "clip color values". Away you go. I save these intermediate files with meaningful names like "IR+G.tif". Oh, and another tip, save working files in TIFF instead of JPEG. JPEG is lossy, and multiple compressions degrade image quality. JPEG in, JPEG out, TIFF everywhere else.