This is just too good to be true... I've always loved how easy it is to make presentations on MS PowerPoint, but we have to admit that when it comes to writing equations, Latex is the way to go.
The bad thing is that Beamer (the latex package for presentations) doesn't have all the nice (and above all "Click and Go") options that PowerPoint has. So, for those like me that want something pretty looking and fast to do, but prefer equations on latex, the solution is Iguana Tex, an add in for PPT that allows you to write equations in latex directly on your ppt document.
Just be sure that you have:
A latex installation (such as MikTex)
The dvipng package
the zhmetrics package
Here is the Iguana Tex site, which includes a very helpful FAQ:
http://www.technion.ac.il/~zvikabh/software/iguanatex/
Another option (which might work better in some cases) is this:
http://thd.pnpi.spb.ru/~gromov/mytexpoint.html
in this case, you should install first pstoedit: http://www.pstoedit.net/
and ghostscript: http://www.ghostscript.com/
and indicate their paths the first time you run the program.