I perfer to introduce a fashionable web 2.0 application is Tumblr. It is a kind of Micro-blog like Twitter and Weibo, but there has many difference from both of them. Firstly, Tumblr is an "show off" product.Thus, the interface of Thumblr is pretty good and very friendly. Secondly, Thumblr has realize the improtantances of collect and social functions in Web 2.0's life. Addtionally, most of blog-user doesn't need write a lot of words to describle their daily life, due to the younger generation pefer to choose a picture to show it. That is a advantage of Tumblr application. It is noticeable that Tumblr is very easy to sign up, through the test by myself, if you have an avaiable e-mail address, the process doesn't needs 30 seconds.