The following command allows a variety of useful operations on files based on stripping their extension:
find . -name '*.dat' | while read f; do echo "$f" "${f%.dat}"; done
The above command listed *dat* file without the said extension. Below we put tar archives in directories named after them (prevention of tarbombs).
find . -name '*.tar' | while read f; do mkdir "${f%.tar}"; done
find . -name '*.tar' | while read f; do mv "$f" "${f%.tar}"; done