Alphabets and Syllabaries
Omniglot is a neat website showing, among other things, all sorts of different writing systems in use around the world. This includes everything from abjads (consonant-only alphabets) to alphabets to syllabaries and all sorts of other stuff.
I had no idea that the Latter-Day Saints had experimented with creating their own alphabet (called "Deseret," of course) back in the 1850s. There are all sorts of other neat writing systems on display--- one of my favorites is Cherokee, which looks like Roman script, but is pronounced completely differently. What I've heard is that Sequoyah had seen printed material in English, which he couldn't read. But he understood its purpose and based the writing for his own language on it. I'm not sure exactly how accurate that is, though.
It's pretty remarkable how many different writing systems one sees on signs just driving around Southern California - Roman, Cyrillic, Greek, Arabic, Hebrew, Ge'ez, Armenian, Hangul, Chinese, Kanji, Hiragana, Katakana, Khmer, and Thai, by my reckoning (most Indian establishments have their signs in English). The one that I can't read that I think would be most useful to learn would be Arabic; I may not know how to speak Russian, but I can at least read Cyrillic script to get place names and such. It's be neat to be able to do the same in Arabic.