Digital BW, The Print

I've always used the Photoshop Image->Mode command when I needed to 
convert a color image to grayscale, but I've seen various references 
to other software used for this purpose.  I'd appreciate any 
information on what software I might consider as an alternative to 
Photoshop for this purpose and also any technical info on what the 
software is doing (whether Photoshop or other) when an image is 
converted from color to grayscale.  Also, any thoughts on how to 
evaluate Photoshop vs the alternatives with respect to the conversion 
process and resulting image.  In other words, in what way would my 
grayscale images be better if I used a program other than Photoshop 6 
do to the conversion?

TIA,

Gary Benson
Eagle River, Alaska