The websites on which these tools can be found are: Twitter.com (Twitter), Wikipedia.org (Wikipedia), Google.com (Google, Google Accounts and Google Apps), Blogger.com (Blogger), Youtube.com (Youtube), Yahoo.com (Yahoo!), Wikimedia.org (WIkimedia), WallWisher.com (WallWisher), Bubbl.us (Bubbl.us) and Skype.com (Skype). It's hard to choose a favourite tool, but I've got to admit I like Google Accounts the most as it enables the user to do the most things with one account. I personally hate having to get a seperate account for each feature, so Google Accounts allows me to use just one account for many tasks. This is why I like Google Accounts the most out of the mentioned Web 2.0 Tools.