Any way to lay out JFBCLogin horizontally?

There really isn't right now. Currently, the module is pretty fixed for vertical layouts. Adding horizontal is something we've had on our radar for a while, but haven't gotten to because it hasn't been requested much lately. One thing we can recommend is finding an alternative Login module that lays out how you're looking for, and then modifying it's template by adding {JFBCLogin} to it. That tag will throw the Login With Facebook into the other login module, and hopefully get you setup right.

I know this isn't the best answer, but if you already had a horizontal module, or don't care about the Joomla login portion, the {JFBCLogin} tag should be able to give you a bit of flexibility. Since we added that tag, our requests for this feature have dropped drastically.. hopefully, this will help you too.

If you need more info, let us know. Modifying the JFBCLogin template would take a little bit of PHP/HTML re-jigging, but shouldn't be horrible. We can help if you want it.