Neat. Some time ago I made a little web site that can turn LaTeX into a PNG file for those times when you need a quick equation (or inequality): http://equationater.com/
I did this a few years back for an independent study in college. Once the semester was over I never touched it again though. Hopefully they'll do a better job.
The interface for Mathematica, which typically consists of bracketing special characters with escape characters, is a lot less cumbersome than LaTeX for writing something quickly. For example, the integral of the square root of x is entered
esc int esc ctrl-2 x left arrow esc dd esc x. Shift-enter evaluates the thing to 2/3 x^3/2.
Yeah it's OK for typesetting books but very verbose for chatting. Though if you need to chat about integrals and the like I guess you are stuck with it.
We're just talking about LaTeX's math mode here. Are there any more concise and easier ways to type math on a normal keyboard and have it display in a pretty way?
and turn it into pretty print. That seems more natural than LaTeX. LaTeX is for getting exactly what you want on paper, at the expense of ease of typing.
Is that harder than $\int_{0}^{100} x^2 dx$? Your version is only 4 chars less, and mine looks more like the actual math...
LaTeX has the added advantage that most mathematicians have it in muscle memory. (I have latex in emacs muscle memory, so I have a hard time using mathim.)
I've been playing with Open Office Math lately, and using it to convert to MathML. It may be worth a look (behaves like the formula insert in OO Writer).
Adium used to have a plugin for this too, which I used to use, but I haven't bothered to see if there's a current version.