I'm using illustrator and I have a graphic that is 22 pixels by 22 pixels. I export it as a png with 72 resolution, and it constantly comes up blurry. Is it just because it's too small? On my mac it looks at least a little bit cleaner than on my pc...
Assuming you mean that "72 resolution" is DPI - Dots Per Inch, it's irrelevant when it comes to screen graphics (opposite to print graphics). Great article (and free ebook as well) on that topic here
Basically what that means is, that no matter how high DPI you set when exporting your graphics, it'll have no effect as you are working with digital units (pixels). Thus 22x22px graphic will look blurry. However, would you want it printed, that's where DPI comes necessary as it tells, in what ratio should pixels be converted to millimeters on physical - printed medium (eg. paper)