Ipe

Ipe - is a drawing editor for creating figures in PDF or (encapsulated) Postscript format. It supports making small figures for inclusion into LaTeX-documents as well as making multi-page PDF presentations that can be shown on-line with Acrobat Reader.Ipe's main features are:
Entry of text as LaTeX source code.

This makes it easy to enter mathematical expressions, and to reuse the LaTeX-macros of the main document. In the display text is displayed as it will appear in the figure.Produces pure Postscript/PDF, including the text. Ipe converts the LaTeX-source to PDF or Postscript when Requirements
PPC, MacOSX 10.3 or lateran installation of Trolltech's Qt/Mac 3.3 C++ Framework libraries (a download bookmark is provided with the installer)