The only quibble I'd have with J's link above is that it should be tittle, with a double 't'. Although the word comes from title, with a single 't', in the specific sense of a tiny mark in writing - ie meaning much the same as 'jot' - the 't' was originally and still is doubled and the word thus pronounced differently.
Quizmonster, regarding jots and tittles, I sometimes wonder if there's any connection to the idea of dotting your i's and crossing your t's. That might suggest a jot is the dot and a tittle the cross. (Jot being, I presume, related to iota.)
I know of no evidence for this, though.
J, There is a tendency to suppose that the jot (from 'iota') is somehow tied to the dot, because a dot is what the letters �i' and 'j' have above them. By the same token, the tittle is often supposed to relate to the stroke on the �t', perhaps because they share a �t' sound. However, either word can be used for the i-dot or the t-stroke, really, or any other such mark...~ � � etc... as thay are, effectively, synonymous. Cheers