Visualizing content/user creation

I'm trying to come up with an easy way of generating analytics for my site. I have Google Analytics, so I know where people are coming from and what pages they're looking at, but I want to be able to visualize when users sign up and when they create content.

Is there an easy way of doing this? Just a simple historical graph of nodes created vs. time would be great. Or users registrations vs. time would be cool.

I thought about exporting tables from the database then processing them in MATLAB/excel, but that's too much work. I want an easy way out!

Any thoughts?