How does one select all friends when trying to invite them into groups, etc.?
Here you have 2 browser plugins for quickly selecting all your friends (actually 50 at a time, which is the current limit set by Facebook):
Facebook Invite All for Google Chrome
Adds an "toggle all" friends button to Facebook groups, events and pages
Easily invite all of your friends to your fan pages, groups, and some apps on Facebook. By default, it will add ALL, but you can select a range if you only want to add a certain number of your friends.
There is Chrome Extension to Invite all Friends to the New Facebook Groups: