Resources for learning Chinese (language & culture)

http://chinesepod.com/
Download free .mp3 podcasts with the basic, free account. Each lesson is a short and entertaining conversation between an English native and a Chinese speaker.
There is also plenty of activity in the discussion panels, where community members help and discuss spoken and writing details about the lessons.

http://fsi-language-courses.org/
Very thorough and authoritative course material developed by the United States government. Each course module contains audio (.mp3), a student textbook (in .PDF format), and a workbook. The lessons are impeccable and demanding.

http://www.pinyin.info/
"This website is aimed at contributing to a better understanding of the Chinese languages and how romanization can be used to write languages traditionally associated with Chinese characters (such as Japanese, Korean, and especially Mandarin Chinese)."
Very academic with plenty of excellent scholarly essays, such as:

• Regarding Chinese characters as "ideograms" or "ideographs" is incorrect
• Chinese characters don't take less space than alphabetic systems. Presents anecdotal evidence of the contrary, despite the fact there aren’t spaces between words when writing in Chinese characters, and Chinese characters handle entire syllables rather than having to spell them out letter by letter
• Why Beijing was spelled Peking
• Common character slips in China
• Why Chinese is so damn hard (tremendous read!)

http://zhongwen.com/
Online dictionary of Chinese characters.

http://www.echineselearning.com/
Online, one-on-one tutoring with native Chinese teachers. Similar to ChinesePod but access to most content requires paid subscription.

[Update, Jan 2013]:
Mr.China

[Update, Mar 2010 via Mariam]:
Skritter
http://www.skritter.com/
Learn Chinese and Japanese characters by actually writing them from scratch. Much better than this Taiwanese school at teaching pronunciation and stroke order.
Slick and easy to use User Interface.


[Update, Apr 2008]:
Nciku
http://www.nciku.com
Dictionary, conversations (text-to-speech annotated with hànzì and pīnyīn), Q & A space, tools, an awesome handwriting recognition tool that let's you draw Chinese characters, and plenty more cool stuff!


[Update, Dec 2007]:
Free Foreign Language Courses Online
http://education-portal.com/articles/Free_Foreign_Language_Courses_Online.html

BBC Languages - Mandarin Chinese
http://www.bbc.co.uk/languages/chinese/

MIT - Foreign Languages and Literatures
http://ocw.mit.edu/OcwWeb/Foreign-Languages-and-Literatures/index.htm

Utah University - Languages, Philosophy and Speech Communication
http://ocw.usu.edu/Languages__Philosophy_and_Speech_Communication

eLanguageSchool.net - Learn to Speak Mandarin Chinese Online
http://learnchinese.elanguageschool.net/

Other interesting resources:
Language Centre in the School of Oriental and African Studies (SOAS) at the University of London.

Comparing American and Chinese Negotiation Styles (Video)

How hard is it to learn Chinese? (BBC News)

88 MOCCA - The Museum of Chinese Contemporary Art on the web

Chinese Contemporary

UK Chinese Music