How do I type using my keyboard on the iphone simulator?

Try trashing the iPhone Simulator preferences file. When my iPhone Simulator stopped responding to keystrokes, this fixed it.

1. Quit the simulator.
2. Go to finder and press (command+shift+G) then navigate ~/Library/Preferences.
3. Move com.apple.iphonesimulator.plist to the trash.
4. Try launching your iPhone app in the simulator again.

Deleting com.apple.iphonesimulator.plist did not help me under Xcode 6.0.1. Probably, it worked in old Xcode.

But, what works perfectly for me under Xcode 6.0.1, it is new hot Keys in iOS Simulator:

Shift-Command-K   Connect/Disconnect Hardware Keyboard
Command-K         Toggle (Show/Hide) Software Keyboard

And, you know, I really suffered for last 2 months, until found it, and it is very convenient now))