I have a basic install of Sharepoint 2010 Enterprise.
I'd like to know where I can view the list of items which I've tagged "i like it" (using the default button included), if such a place exists by default.
Click your name in the top-right corner of the page to bring up the welcome menu. From the welcome menu, choose "My Profile." Select the "Tags and Notes" tab and you'll be able to see everything you have tagged with "I like it" (as well as any other tags you may have used for content in SharePoint).
For more information, see this blog post.