The TI-89 Titanium is a fantastic device from the same people that brought you the TI-83. Chances are, if you are in the market for a TI-89 you have already had a TI-83 for a few years now and are trying to decide if you should make the jump to the 89. In short, my answer would be "go for it". The TI-89 provides all of the features that the 83 did but with a beatuful screen and more features. One of the best features of the TI-89 is the ability to review your calculations and use them again. For instance, if you accidently just typed "x+25" but meant to type, "2x+25", you could go back and "grab" what you just typed and edit it. The TI-89 also allows for character manipulation, meaning that you can take derivatives and integrals of functions. The TI-89's most popular feature for many students is the solve function. The calculator can take any equation and give the answer almost immediately. No more quadratic formula! One final note; the TI-89 is not the most durable calculator in the world. While it is difficult to damage the screen of the inside, the outer casing has cracked for me several times and there are pieces of plastic missing. Though this doesn't affect the actual calculations at all, it doesn't look quite as nice as it did before.If you are a student who is in Calculus or is going to be in Calculus, you WILL NEED this calculator, so the sooner you buy it the better. For everyone else, it's just a useful tool that will make your life easier.