Hosting Websites Directly from Dropbox
Dropbox is an easy way to create a quick website without the need for a server. You are limited to client side scripts and HTML since Dropbox cannot run any server side stuff.
Create a folder in your Public folder for your website. Put your entire website under this folder. Right click on the homepage of your website (usually something like home.htm or index.html) and get the public URL for it. Bookmark this URL. You can share this URL with your friends, and let them access your website.
If you own a domain, you can create a CNAME record that points to dl.dropbox.com. From this, you can create links such as dl.domain.com/u/[DropboxID]/pic.png. For more information, see here: http://forums.dropbox.com/topic.php?id=7897&replies=17.
Hosting Websites from Dropbox using KISSr
KISSr enables you to host websites using your own domain name. KISSr is free to use for for third level domains (eg. yourdomain.kissr.co) and has very affordable rates on second level domains (eg. youdomain.com)
If you are looking to set up Dropbox as a web publishing platform like git or svn, please see this article here.