accentuate.us is pretty cool (except that it does not work yet in either of languages that I need it for):
Dataists.com: "Many languages around the world use the familiar Latin alphabet (A-Z),
but in order to represent the sounds of the language accurately, their
writing systems employ diacritical marks and other special characters. [...] Speakers of these languages have difficulty entering text into a
computer because keyboards are often not available, and even when they
are, typing special characters can be slow and cumbersome. [...]
To solve this problem, we have created a free and open source Firefox add-on called Accentuate.us
that allows users to type texts in plain ASCII, and then automatically
adds all diacritics and special characters in the correct places."
