Free Technology for Teachers: Gives step-by-step instructions for using Google Docs' forms and spreadsheet capability for creating an online quiz that can be easily graded inside a spreadsheet.
Free tool that allows you to schedule an event by creating a set of possible times and then asking recipients to click on the ones when they are available. ("Schedule an Event")
Also allows creation of a one-question poll ("Make a Choice").
See "Help" for instructions.
Extremely easy to use. You need to create a free account.
Free tool for creating PDF files from documents. Very easy to use, creates very small .pdf files. Not strictly web2.0, but allows creation of files to share online