While these cool sites are not specifically public health oriented, they certainly have potential applications… And they are free!

LibraryThing.com
LibraryThing.com is an online service that allows registered members to catalog their books online. Registration is easy and individuals, book clubs, and non-profits can catalog up to 200 books for free. This very easy to learn application allows members to search the Library of Congress, all five national Amazon sites, and more than 45 world libraries to find their books, but also lets users add items manually. If you are looking for a place to catalog your collection of books, pamphlets, articles, or handouts, you may want to check out LibraryThing.com.


Writely.com
Writely.com is a free, Web-based word processing application that allows up to 50 collaborators to create, share and edit documents online. Recently purchased by Google, Writely.com allows you to upload Word documents, OpenOffice, RTF, HTML or text (or create documents online), format, and spell check them, share editing duties, track changes with a revision history feature, and post or download them to your desktop.


del.icio.us
del.icio.us is a free, social bookmarking website: it allows you to store your bookmarks or favorites online, tag them, and share them with others. Tags are one word descriptors that work something like keywords or categories, helping you to organize the website links you visit. del.icio.us is a great way to collect links on a particular topic and share them with a workgroup.


WetPaint
WetPaint™, a Seattle company, “allows users — especially those without technical skill — to create and contribute to websites written for and by those who share a passion or interest.” WetPaint™ is a type of wiki or collaborative software, but does not require webpage developers to know complicated programming language; you simply click and type.