IguanaTex is a freeware that help you to insert math formula, equations using into Powerpoint presentation. I don’t know exactly which version of MS office it would work for, but at least it works for MS Office 2007. If you are familiar with , then this will definitely help you to write math equations in Powerpoint real fast.
There are a lot more in this forum:
I came across this blog very helpful for learning Japanese. The blog contains tons of e-books, video courses, learning softwares, Japanese movies, Japanese aminations, etc. You can find all Japanese things there. Also you can download them!