I want to use Theorem-like environments in Latexit.
How can I do this?
Take a look at this image:

I have pulled down the little hidden panel for the preamble, and added the amsthm package. I have also added a definition for an unnumbered theorem environment.
In the main box I've placed a little example.
As usual, you may now drag and drop the typeset snippet where you like. If you want to use the proof environment too, you may want to tell that environment not to use a Q.E.D. symbol, as this will appear way over to the right. To do that add
\renewcommand{\qedsymbol}{}
to the preamble.

\text{...})". However, this is more to do with the way LaTeXiT has been set up than with TeX so you'd probably be better off emailing/contacting LaTeXiT's support rather than asking here. – Andrew Stacey Jan 06 '12 at 11:20textbutton to work in text mode. Topologieeeee, can you put a MWE of a document with a simple example of what you'd like to achieve in LaTeXiT, and I'll see about some instructions for you. – qubyte Jan 06 '12 at 12:07