Windows Phone 7, like most modern touch screen phones, has an on screen keyboard. It’s known as the Software Input panel (SIP) and it is a virtual keyboard that appears when a text-input control such as a TextBox gets the input focus.
There are 50+ keyboards configurations available. Figure 1 shows the default keyboard layout.
Figure 1: Default SIP
How to input accented (diacritical ) characters
It is simple to input accented and alternate letters if you know the secret. Press and hold a letter on the SIP to see the available list of alternate characters.
Here are some sample screenshots.

[...] Accented characters on the Keyboard [...]
[...] Accented characters on the Keyboard [...]