I would like to be able to sort a selected column block or other selection and the sort be done in-place.
there are plenty of sort algorithms, the fastest usually being qsort with mergesort for the subsections. I don't know how they do that, but at least a qsort/quicksort could be done. I am sure you could find the algorithm on wikipedia or use the c library function for it. I think STL has something for that. faster and better version of qsort would be introsort by SGI.http://en.wikipedia.org/wiki/Introsort
this is the kind of feature you will find yourself using over and over and over periodically on data and lists and documents, html files, etc.