Typing umlauts and accented characters without the one second delay
I don't know a direct solution to your question: Reduced delay. If your iPhone is jailbroken you might be able to find the preference file that sets the delay and reduce it.

One work around could be to not deal with the accents at all and have the iPhone insert them for you, as autocorrected words. You can now type full speed.

To add custom words to the dictionary:


Add the Japanese Ten Key keyboard: Settings > General > Keyboards > International Keyboards > Add New Keyboard > Japanese Ten Key.
Add words: Settings > General > Keyboards > Edit User Dictionary.
Have the Word be what you want to type w/o accennts, and the Yomi be the accented work.


For example, I added Word=fooxx and Yomi=föoxx, I then went to the Notepad and using the English keyboard I typed "fooxx", and the iPhone suggested föoxx. When I did this example without the "xx" it did not work, perhaps because foo is already in my dictionary.

Alternatively, if you iPhone is jailbroken you could try using Xpandr