[PhilJ]

Slight addition which adds a checkbox to copy the e-mail field to the username field.

in skin1/check_email_script.tpl add the following code:

{* COPY E-MAIL AS USERNAME MOD *}

{literal} 
<script language="JavaScript1.2"> 

var uname = "";

function InitSaveVariables(form) {
uname = form.uname.value;
}

function copyemail(form) {
if (form.copy.checked) {
InitSaveVariables(form);
form.uname.value = form.email.value;
}

else {
	form.uname.value = uname;
	}
}

</script> 
{/literal} 

then in skin1/main/register_account.tpl just below the comment

{* NOT anonymous account *}

add this code:

{if $userinfo.login ne "" || ($login eq $userinfo.uname && $login ne '')}
{else}
<TR>
<TD align="right"></TD>
<TD></TD>
<TD nowrap>
<input type="checkbox" name="copy" onclick=javascript:copyemail(this.form);>Use E-Mail Address as Username
</TD>
</TR>
{/if}