The value of post-it notes to knitters has not been publicly acknowledged. I use them constantly, and even carry little pads of them around with my various knitting projects. Why? you ask...They are perfect for keeping my place on a pattern or on a chart, and I can even mark them up as I keep track of the number of rows I've knitted.
Since I am going through a charted pattern phase as a preliminary to a knitted lace phase, I've found that post-its let me work my way through a chart without constantly losing my place, and they're not displaced if I close the book, fold the pattern, or am interrupted by a cat.