Is there a list of the $vbulletin->options[] that are available?
 

I am trying to manipulate some things via $vbulletin->options['variable']='value';

How do I find out what all the options variables are to change? The guessing approach is getting old. :)

Hover over the area you'd type in on the vBulletin Options pages. A small message will appear next to your cursor with something like "options['var']".Whatever "var" is will be the text you put into $vbulletin->options['var_here']

Sometimes its helpful to see the whole list! Try printing out the entire $vbulletin variable, something like:

You can also drill down, lets say you want to see all the userinfo variables, just use $vbulletin->userinfo.