We have tools to show this in our moderator section but as we're not allowed to show you any of the detail in there (of which this probably counts) I built you a query on data.stackexchange.com:

 - http://data.stackexchange.com/ubuntu/query/80302/new-users-per-day

Those are the "new user" counts for each day. If you want a running total, you'll need to build something that accumulates a running total (fairly simple, either in a script or a spreadsheet).

Note: the data on that site isn't live. The latest data on there at the moment is from the end of June. They do dumps every few months.

Can I see the graph when it's done?

##Edit: Got bored; made a graph.

![enter image description here][1]

You can download the spreadsheet from:

 - http://people.ubuntu.com/~oli/au-users-20120626.ods


  [1]: https://i.sstatic.net/Ka2Lk.png