Calculators have no place in a teaching environment. If they want to learn to use a calculator later, read the freakin’ manual. I could get behind allowing the use of a slipstick for classes after Algebra II.
Anything that has a practical application in the real world most certainly does has a place in a teaching environment. Calculators can do things most human brains cannot. Professionals from office assistants to scientists use them on a daily basis, and the average person isn’t going to learn advanced functions by tinkering around with an instrument he or she has never touched before. Imagine an employer asking an interviewee whether he or she has experience performing advanced functions on advanced calculators, and the interviewee replies, “No, but I can read a freakin’ manual.”
Students shouldn’t be encouraged to use calculators as a crutch or as an excuse not to master basic arithmetic, but there’s nothing wrong with using calculators as tools in higher-level math.