This is the correct answer, not sure why Blaine only left it as a comment!
As of iOS 6 Remote Debugging is available: https://stackoverflow.com/a/12762449/72428
On OS X you can use the Safari web inspector on the iOS Simulator AND iOS 6 devices.
- First enable the Developer menu in Safari on your Desktop.
Next, enable remote debugging on your iOS device (or simulator).
Settings > Safari > Advanced > Web Inspector (ON)
Go back to Safari on your computer, click the Developer menu, and select your device (e.g. iPhone Simulator, iPhone)