I discovered a great little iPhone shortcut yesterday. When entering a URL, you get a dedicated button for '.com', but, like when you can hold down on a letter and have accented characters pop up, if you press down on .com, you get the option of switching to .co.uk.
This relies on you having set UK English in your keyboard preferences (Preferences > General > International), and if you pick any of the other options – French, German, Italian – you get other region-specific options from popping up the '.com' button.
