The present invention relates to novel phosphate isosteres. The invention relates to compounds having a sulfhydantoin or a reverse sulfhydantoin moiety, uses thereof, and related methods. The present invention relates to compounds of formula I or II: ##STR00001## or pharmaceutically acceptable salts thereof; wherein Q, T, m, and X are as described herein. These compounds are inhibitors of phosphatases, particularly inhibitors of SHP-2. The invention also provides pharmaceutically acceptable compositions comprising the compounds of the invention and methods of utilizing these compounds and compositions in the treatment of various phosphatase-mediated diseases.