I tried various ways to output a sorted countries list, changing the country I wanted at top to be ID 0 and whatnot, didnt work. Finally I relaized I was overlooking the obvious of using <option .... selected>
Thankfully, the requisite functions have built-in "selected" handling, thus setting your default country is easy.
Edit create_account.php and find
<tr> <td class="main"><?php echo ENTRY_COUNTRY; ?></td> <td class="main"><?php echo tep_get_country_list('country') . ' ' . (tep_not_null(ENTRY_COUNTRY_TEXT) ? '<span class="inputRequirement">' . ENTRY_COUNTRY_TEXT . '</span>': ''); ?></td> </tr>
you want to change this line
php echo tep_get_country_list('country') .to be
php echo tep_get_country_list('country','223') .223 == the country ID for United States. YOu can set that to be any country by looking either in the database countries list for your countries ID, or even easier, look at the HTML of the create_account.php page and find where the country drop down list is, search for your country and grab the "value".
Hope this helps.