I found a cool app for 4.99 for my Droid called "animated knots" by "grog llc".
It's got catagories such as basics, boating, climbing, fishing, etc"..
Sequential pictures of many different knots and the pics are reversible. I think it'll be very helpful learning some new knots.
Knotwork has always been very interesting to me. My conversion from ground to hanging has given me good reason to learn some more.