You may enjoy this: http://www.intuitor.com/hex/learn.html. We should have another contest some time. Knowing hexadecimal is useful because 1.) it helps you get a better handle on the foundations of arithmetic, and simultaneously teaches you octal and binary, and 2.) it helps when you use computers.
"The presentation or 'gift' of the Holy Ghost simply confers upon a man the right to receive at any time, when he is worthy of it and desires it, the power and light of truth of the Holy Ghost, although he may often be left to his own spirit and judgment." --Joseph F. Smith (manual, p. 69)
"Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me."