In addition to the obvious knitting and crocheting uses, this yarn can make a wonderful twine. Consider beading or other crafts, and definitely think about making washcloths -- your face will thank you for the exfoliation, and hemp's anti-mildew properties will come in handy. (Note: It's not that hemp CAN'T mildew, it's just less likely to do so. Keep that in mind, and do let your hemp items dry thoroughly.)
The thinnest yarn, hemp3 is fingering weight, 1569 meters/1700 yards per pound, 28 st and 38 rows over 4 inches when using 3 mm (2 US) needles.
The medium version, hemp6 is dk weight, 785 meters/850 yards per pound, with a gauge of 22 stitches over 4 inches when using 3.75 mm (5 US) needles.
The thickest of the three yarns, hemp12 is worsted weight, with 392 meters/425 yards per pound.
Purchasing a swatch will give you pieces of all three thicknesses; there's no need to specify which you want. Do expect some color variations, because of the natural shade differences in hemp fiber.