How can I avoid iphone safari first letter in caps

Edit: use "none" instead of "off". On your webpage, all you need to do is set the autocapitalize property to off for your input field. So:

<input autocapitalize="none">

See the Safari Web Content Guide: Designing Forms and Safari HTML Reference

Below is the answer I had before, which relates to native apps. Keeping around for anyone who's looking for that answer.

From the UITextField Documentation

The appearance of the keyboard itself can be customized using the properties provided by the UITextInputTraits protocol. Text field objects implement this protocol and support the properties it defines. You can use these properties to specify the type of keyboard (ASCII, Numbers, URL, Email, and others) to display. You can also configure the basic text entry behavior of the keyboard, such as whether it supports automatic capitalization and correction of the text.

So basically, the UITextField supports this protocol. The property needed is the autocapitalizationType. An example in code is:

myUITextField.autocapitalizationType = UITextAutocapitalizationTypeNone;

or if you dislike the dot notation:

[myUITextField setAutocapitilizationType:UITextAutocapitalizationTypeNone];