The following may seem picky, but I have not found any way to display the 
equation of a regression curve on a scatter plot.  I am able to display 
linear, logrithmic, exponential, and power regression curve, but that is all.  
I find the following features of the spreadsheet component lacking. I explain 
myself below:  
First- the display of equation of regression curve.  I realize that 
the "LINEST" and "LOGEST" commands are able to give the equation of linear and 
logrithmic regression curves, but what about exponential or power curves?  It 
seems to me that if the spreadsheet component is able to generate a regression 
curve on the plot it should be able to give the equation of that curve at the 
same time, along with some indication of the accuracy of the estimate.

Second- once a regression curve is added and the file is saved, upon sharing 
the file with MS Excel (or saving the file as .XLS) the curve is gone when the 
file is reopened in OpenOffice.  This also occurs upon opening a spreadsheet 
created in MS Excel with a "trendline" or regression curve- when OpenOffice 
opens the file the curve is absent altogether.  Is this a conversion error?

Third- this one is least important, but a feature nonetheless.  It is 
sometimes beneficial display data in a plot with one or both of the axes 
reversed- that is, the minimum and maximum values are unchanged but one or 
both axes are "mirrored" or reversed in the plot.  MS Excel has this feature, 
but I have not been able to locate it within OpenOffice.

Thank you for your attention,
khazmat