Update multisite modules and core in one click I have a Drupal multisite install with 7 different sites, all sharing the same modules, themes and users but everything else is unique to the individual site.  At the moment, I only have to upload one version of Drupal core or any contributed modules when I want to update them but I have to run update.php on each website separately.  Is there an easy, quick way of making all of these updates run simultaneously?
I think the simple answer is no. And generally you would want it to be so.

Running update.php can cause sites to fail, so you should back up each sites database run update.php and then check it works. Each of your sites will work slightly differently, depending on the combination of modules. So a broken update hook, or a conflict would be something that you would want to check carefully for. 

Having said all of that there are tools such as aegir which may make this possible to do safely.