[BirdOPrey5]

Fairly easy to do.

1) Create a User Profile Field: "Use Horizontal Postbit?"
Answers: Yes / No
Note the field # it is given after you save it. (Field # may be different then display order)

2) Go to Plugin Manager -> Add New Plugin
Product: vBulletin
Title: Custom Postbit
Hook: global_bootstrap_init_start
Exec. Order: 5
PHP Code:

PHP Code:

global $vbulletin;
if ($vbulletin->userinfo['field5'] == "Yes")
  $vbulletin->options['legacypostbit'] = 0;
else
  $vbulletin->options['legacypostbit'] = 1; 


*Change 'field5' to whatever actual field# it is assigned- 'field6' , 'field7' ...

Then anyone who chooses "Yes" will see the horizontal postbit, and anyone who chooses "No" (or doesn't choose at all) will see the legacy (vertical) postbit.