Are there scientific analysis packages /addins available for excel?

hi there,

I've been doing some analysis of data I have with excel. I find it easy to use and very helpful, but find sometimes its scientic analysis capabilities somewhat lacking, especially in creating and manipulating charts the way that Sigma Plot or Grapher can.

I am not the most experienced excel user so excuse my limited knowledge, but is there an excel addin or scientific plotting package for excel somewhere? If not, do you think the makers of excel would upgrade its already powerful graphing capabilities in future versions???

just a thought to throw out there....