Google Docs - Has a word processor, a spreadsheet and a presentation component that is similar to other commercial office suites, such as Microsoft Office.  Google Docs allows you to save your document in many popular formats.  In addition, Google Docs allows for collaboration, which means you can share your documents with other students.

Scribd - Uses iPaper which transforms Word, PowerPoint, PDF and other common formats into easily viewable Web content.  Scribd allows users to make documents private or public.

Issuu - Allows you to upload documents that might normally be published; including magazines, catalogs and documents.

HowToWriteAResume.net - Allows you to build a resume from start to finish and even distribute it to the major job posting sites.  While the site does require payment for certain resume format the basic format is absolutely free.  You can save your resume as either an html file or a text file.

EasyBib - An automatic bibliography and citation maker.  Create citations in MLA format for free.

PitchThenPlan - Allows for the creation of a business plan.