If you need to get a quick and simple web page up, these services work with Dropbox to let you do it for free.
Pancake.io allows you to take any text file and put it on the web. You can also use HTML and the simplified Markdown language (see http://support.mashery.com/docs/customizing_your_portal/Markdown_Cheat_Sheet) to display more complex layouts. Signup is quick and easy and you edit the files in the website interface or in a text editor. The URLs are a bit messy, but they have pledged to improve this. You can also upload PDFs and other documents.
A better, if slightly more complex, option is DropPages.com. It does basically the same thing as pancake.io, but gives you more options and more advanced layouts (with themes). You also get a better URL – anythingyoulike.droppages.com.
Neither of these will work well for multi-page sites or complex layouts, but for a quick, free way to get a website running they are tough to beat.
Note that Dropbox bandwidth limits of 10GB per day (250GB for Pro users) still apply, although these are unlikely to impact you unless you are expecting a great deal of traffic.