The apathy's understandable... 'ten thousand words till my next rejection or a marathon session of Powell and Pressburger?" can often seem like a simple choice, but you have to learn to fight that. The laziness, I can't do anything about, apart from to remind you a) how much you hate your day job, b) How galling it is when you see all those 'talentless hacks' out there ruining great ideas (i.e: the ones who've got the gig instead of you) and c) DO YOU WANT TO BE A WRITER OR NOT, YOU BONE IDLE BUGGER?
But, assuming that your indolence isn't down to laziness, and its either apathy or that occasional and unavoidable blank space in your imagination, that's not an excuse not to be writing.
That piece you're working on and can't seem to get past the next line? Go back to the beginning and read it. It's quite frightening the number of writers I've come across who don't actually read their work more than once - if that - before delivering. If you don't start re-writing by page 3 then you're probably an arrogant son of a bitch who'll never sell a word (or make millions mimicking John Sullivan and praying no-one notices).
Dig out all the old notebooks (You do carry a notebook everywhere you go don't you? Please dear god tell me you do... and no, a dictaphone doesn't count). Marvel at those nonsensical jottings and see if any shapes and structures or characters and coves crop up.
If that doesn't work, how many manuscripts, novels, poems, well constructed shopping lists have you got sitting in the graveyard of your files? Open them up, look through them, edit them or bin them.
Remember that writing is just as much about deleting as it is about filling the page with verbage. Knocking ten pages off a script can be ten times as productive as adding ten words to it. Some people imagine that writing is racking your brain to find the next word or sentence. Sometimes its about racking your brain to eliminate all the possibilites bar the perfect phrase. There's no shame in finishing an eight hour day, looking at your work and thinking 'brilliant - I just deleted 5000 words'
Alternatively of course, you could just write your blog :-)