I found Wolfram Alpha to be immensely useful when doing chemistry work back in undergrad. Just input a chemical compound and see what it spits out. Now imagine being able to call any of those pieces of data during calculations using a string, e.g. "molecular mass of Na2SO4". Very convenient, simplifies many calculations.

Another thing that may seem obvious, but you can input multiple strings and get a nice visual comparison. For example, try "cleveland, detroit, flint".