Firefox – in Firefox, how can I prevent new tabs from being opened automatically

I've had webpages that would repeatedly spawn new tabs with various ads, each using a lot of memory due to the flash player plugin.
once in a while Skype would do it too, when it opens the browser to display an add(which happens every so often, not sure if those are still in rotation today but they were a couple days ago) and that adpage would also exhibit this browser based forkbomb.
I don't want to disable Javascript completely, so noscript or turning off the JS feature would be a bit extreme. is there a way to prevent new tabs and windows from being opened like this?