Switch tab shortcuts, or, full shortcut management.

Safari does use ⌃⇥ on my machine. I'm using Mac OS X 10.8.4 and Safari 6.0.5:

Xcode uses ⌘{ and ⌘}.

Ah, but try ⌘{ and ⌘} in Safari anyway.  ;)  While the menu says one thing, for interoperability reasons (Xcode, Terminal, various other tabbed applications *coughfinderonmaverickscough*) Safari allows a variety of shortcuts to be used.  Even ⌘⌥⇧← and ⌘⌥⇧→ work.  Yes, the latter pair is kinda nuts.

Edited to add: because of the consistency across the applications I use for both development and outside of work I've muscle-memory trained ⌘{ and ⌘} -- it simply works everywhere.  Adium has a drop-down allowing you to select which pair of shortcuts to use for tabbed navigation, including now all of the above mentioned styles.  Note that ⌘{ and ⌘} is the only combination that works in Terminal.app without painful global remapping in System Preferences.

I guess it depends on the keyboard layout. The default shortcuts on a German system are very different from the ones you're describing. I've added it to my todo list.

I also vote for this feature. Not only ⌃⇥ is a new shortcut to remember but if I'm not mistaken; it is the default shortcut to switch between spaces in OS X, making the shortcut unavailable for other apps.

Ah, no, the spaces shortcut is control+arrow keys, not tab.

My bad, thanks for the correction. I was confused about the tab symbol. Regardless I still vote for this feature since I really want to use ⌘{ to switch between tabs.

+1 for this keyboard shortcut. Almost all apps (Chrome, Messages, Sublime Text, Coda) on my machine (US) use ⌘⇧] and ⌘⇧[ to switch tabs. It's a small feature I would really appreciate. Keep up the great work!