Have just finished this small cap for my grandson because he likes pirates but think it could also be suitable for an older boy because it is a bit querky and perhaps could even be considered 'cool.' This pattern is small as written but suggest using larger needles for an adult size cap or perhaps adding an extra 14 sts to allow for an extra pattern repeat. http://www.ravelry.com/patterns/library/adrians-skull-cap Make note of the errors in the pattern - 8 repeats; K 28 sts between markers. Used 8ply wool with 3.4mm needles for 1x1rib and 4mm circular needles for body of cap. Pattern is 14 sts x 11 rows.
And used the first of my newly acquired wool stash that I bought last week at Australian Country Spinners mill shop, for a charity knit for an older child http://www.auspinners.com.au/ Free pattern on the right of this post as Child's Vest.