Working from the AdWords Editor can definitely be work, sometimes even a chore. It certainly can feel that when when you have an existing ad group that you want to clone, break up into smaller ad groups, or even copy keywords on the fly in the Web UI.
Since Google is all generous with their constant updates and changes, this week we have been granted a brand new functionality! Now, you can cut and paste while in the UI.
With this new function, you are able to copy anything from keywords, ads, to ad groups, and even entire campaigns. You can access the copy and paste options in the Edit menu drop down. To make things simpler, you can use Ctrl-C/Cmnd-C and Ctrl-V/Cmnd-V, just as you would in a word editor.