GreaseMonkey like feature
 

With the great way to attach individual preferences to web pages in OmniWeb, a GreaseMonkey like feature that allow to customize the way a web page is displayed would be absolutely amazing !
With the thousands scripts available already for GreaseMonkey, like Encrypt feature in Gmail for exemple.

I think there is a such extension for Safari which is compatible with GreaseMonkey scripts that will not use Firefox specific functions, so an equivalent in OmniWeb would make it definetely the best.