Resources
These are two of the coolest resources out there on the web.
One- WolframAlpha is for you math/science people out there. Basically, if it can be calculated, WolframAlpha can do it. It also includes a lot of data that isn't really related to math or computation at all. Some incredibly helpful features include: listing alternative forms of equations/expressions, a variety of socioeconomic and geographic data, anagram solving, and showing steps to solve an equation. Since its beginning, WolframAlpha has undergone a lot of development, especially in the addition of information on non-computational subjects. There are examples available to demonstrate syntax when necessary.
Two- EasyBib is aimed at students of the humanities and social sciences. Basically, any one who writes papers can use it. Given a minimum amount of information, such as ISBN, EasyBib will develop a bibliography entry in the format of your choice. EasyBib is particularly useful with tricky sources, like a map found online, a congressional publication, or a mailing list. It's also great if you have the ISBN number for a book, but can't find a particular piece of data to fit in the MLA formula. I would still recommend knowing your sources well enough to cite them yourself, but EasyBib is fast, and is open at midnight the night before your paper is due, whereas the good old library might not be.
Disclaimer: I personally believe in being honest about your work, but I also think that these tools can be useful for honest purposes. WolframAlpha in particular could be abused, but I would rather believe that every student in the world is just checking their answers, or better yet, is using it on optional problems to increase their understanding of the material. Idealistic, maybe. But maybe the world should be that way.