With ⌘+Y you can enable or disable all of them.
With ⌘+7 you can actually see all of them.
In the previous Xcode versions,it is ⌘+6
Other useful shortcuts:
http://www.1729.us/xcode/Xcode%20Shortcuts.pdf
https://web.archive.org/web/20120518183100/https://pragmaticstudio.com/media/Xcode4Shortcuts.pdf