BuddyPress.org

Using the Javascript trick: 1. make sure the Javascript is included in the head, 2. add onkeyup=”copyinput()” to the input tag for the Username, 3. edit the Javascript so that this line…

document.getElementById('blogname').value = tmp;

…has the id of the input tag for the Name, instead of blogname. The Javascript would copy the input for username upon typing to name.