CyberAtlas: The World's Online Populations
Survey of the number of online users in over 60 contries. Published in February 2002.
http://cyberatlas.internet.com/big_picture/geographics/article/0,1323,5911_151151,00.html

Global Internet Statistics
Offers charts of the estimated number of people online in each language and each country as well as projection for the coming years.
http://global-reach.biz/globstats/