Are you really, really, really stuck for an idea of what to blog about?
Well, you can always do the random blog. What is a random blog? Well, basically it is a blog about anything and nothing all at once. It is a blog about whatever happens to come to your mind when you sit down at the computer and begin to type. It is a blog about you and the people you know (though anonymity is recommended). It is a blog about what you do and what you wish you could do and what you do not do. It is a blog about what you know and what you suspect and what you wish you knew.
In short a random blog is just you typing whatever you want to type.
Most random blogs, however, turn out to be mostly nothing because it is hard to continue to write without focus. So you may want to bring some focus to your blog, which you can find by reading this blog.