LOL, might help to actually let the guy know
how to offer this to his members! I doubt he was asking just a yes/no question.
Assuming you have vb3, go to your admin control panel and click on the "VBulletin Options" menu. Select "Style and Language Settings." Then look for the option that says "Allow Users To Change Styles" and choose "YES."
Next, go to the Styles & Templates area, click on Style Manager, and find your new style name. Choose "Edit Settings" in the dropdown menu. There's an option that says, "Allow User Selection" -- make sure that YES is checked. Do this for each style you want to offer your users.
Hope this helps.