Yeah, fucking can be used in place of any adverb or adjective that implies emphasis

This is fucking hard. 

Ain't that the fucking truth? 

As with all swears, be careful with whom you use it! Some people will be really offended, others (especially us language-people) can use it every other sentence! Some people even use it playfully! Just be careful. :) 

Errr... when is it not a swear word? :)

In many cases, it loses its literal use and just becomes a (vulgar) emphasis.  Pop it in the place of an adverb (ie. those adverbs which describe adjectives).