Problemsolving Tools for the Classroom

I am exploring ideas on effective problemsolving tools for classrooms (K-12).  I'm particularly interested in any technology that has enhanced this type of higher order thinking skills in students.  I'm also interested in learning of success and challenges you may have had in trying to use tools available.  Were your students receptive?  Does your school support you in implementing collaborative technology in the classroom?  Do you find that using specific tools has enhanced your lessons?