There is a fantastic graphics tool called Gimp that is available for FREEFREEFREE on line at www.gimp.org (Note to the techno-challenged like me; you have to download the 'environment', the program, and the help text separately. It took me way too long to figure that out.)
Anyway, since downloading this thing (works just like Photoshop, but less confusing, and did I mention it's FREE?) I've been playing around, trying to get the hang of how it works. Maybe my next Knitty article won't look like the graphics were done by a seventh grader using Paintbrush. (I insult seventh graders; I'm sure they're better at graphics programs than I am.)
So if you need an imaging program, hie on over to Gimp and get one and spend the thousand bucks you've been saving up for Photoshop to buy yourself some yarn.