Do you know what a "tittle" is? Get your mind out of the gutter, silly. It's what you call the dot on the letter i. Or how about "mispell" - what would you call that? It's a haplography: "the accidental omission of a letter or letter group that should be repeated in writing." (The word should be misspell; it's, um, misspelled.)
Only Anu Garg, the founder of Wordsmith.org, can make word facts this much fun. His book, A Word a Day (Wiley, $14.95, 194 pp), is full of this stuff, with chapter names like "Words for Body Parts That Are Used Metaphorically," "Words Not to Put on Your Resume" and "Words That Make One Say, 'I Didn't Know There Was a Word for That!' " Garg writes: "This book is an expression of the joy of words, the magic of words, the music of words" - a real yawnfest for bibliophobes (people who hate books), but a side-splitting lesson plan for bibliophiles and word lovers.