I am a machine knitter as well as a hand knitter and crocheter. Though many people knit and crochet, there were few machine knitters. There are probably 2 reasons - expense and time. Knitting machines can cost over $1000!! And then you need the rest of the "stuff" - ribbers, tools, yarn winders, etc etc etc. And the learning curve is very steep - you HAVE to take lessons before you knit the first stitch (actually it is next to impossible to get started without someone showing you).
A knitting machine is about the size of an electronic keyboard. There are different sizes of machines for different yarn. Yes - that means if you have an expensive machine to knit sports weight yarn, you will need ANOTHER expensive machine for bulky! YIKES! Generally there are 4 sizes - lace, standard, mid and bulky gauge. My standard has 200 needles (and, yes, they are SHARP). They look like little latch hooks. A carraige runs over the needles and makes the stitch. One pass of the carriage equals one row. That is where the speed comes it.
My main business is making scarves and hats for fundraisers. I have done scarves for schools, symphonies, swim teams, soccer teams, graduating seniors, class reunions, family get-togethers etc. I design the scarves with the chosen colors, words and designs. Here are a few: http://www.flickr.com/photos/blazingneedles/sets/72157603877767278/
Next installment - How do you get the designs in there?