Keep Notes: Even when you aren't writing, you are living life. If you have eyes to see it, inspiration is everywhere; pay attention and you'll find many things to cultivate your writing skills. Write these things down and when you sit down to write again, you'll have a ripe field of what I call "small-sight": the little half-noticed things of reality that cross the frail line between stilted and vibrant writing.
Do Dishes: I don't think well while sitting still; for some reason the moment my body is completely still, my daydreams kick in and my mind is off on its own merry way which, sadly, never seems to junction with my WIP's. I know we've all heard it, but it's worth saying again: Agatha Christie swore by doing dishes to bring on a bout of inspiration. Maybe her point was because most people don't enjoy doing dishes so they'll feel like writing just as soon as they've begun the dishes. I like washing, however; proving her theory true, I put my mind to plotting out The Baby the other afternoon and ended with quite a few good ideas. For me, I think my creative brain is stimulated by doing something that doesn't require active brainpower but is productive. Sitting down with nothing to do is my body's signal to space out for a while. (Which, perhaps, is why I love to read so much.)
Watch an old favorite: Funny enough, one of my favorite things to kick me back into a good creativity-spell is to go back and watch a favorite movie: something that is so familiar to me that I can quote it forwards and backwards. Something that draws out the simplest, most important parts of me and brings them back to the light. Usually it's a movie I haven't seen for a long time, but that I love all the same. There are some films that actually have an adverse effect, such as The Lord of the Rings trilogy; when I watch these, the hope of crafting stories that great seems a weak one at best. Some of the movies that work for me? The Sound of Music, Miss Potter, Anne of Green Gables and Anne of Avonlea, Little Women, and Roman Holiday as well as any of the Pixar films.
Write a letter: One of the reasons I keep blogs is because I find that writing fiction and fiction only is actually not that great of an idea. I can easily be tricked into thinking that I'm sick of writing (I know, shocking) when actually what I'm sick of is this particular aspect of this particular story. The best cure for this kind of ennui is a good foray into something logical that still stimulates the need/desire to write. Blog about something entirely unrelated to the topic of writing, or better yet: shut down your computer. Take out some paper and write a letter. Just putting the current events of your life or your recent thoughts into a tangible form is amazing therapy for the novel-weary author.
Work: We authors tend to think that our work as a writer is the only work we will stoop to doing. Believe me, I've been guilty of this. In our heads we're already well on our way to being the next Dorothy Sayers or Percy Jackson; only problem is, the world doesn't know. I'm here to tell you that getting your tail out the door and grubbing around in the garden or painting a dining room or whathaveyou is far more beneficial that you'd think. You might consider menial work below you: oh well, get over it. Even a few days of labor in a row with no writing involved can be better for your novel than three days of a 500-word plunk that you'll end up rewriting anyway. Trust me.
Play with words: Sometimes just being around the comfort of words is enough to inspire. Play Scrabble. Read a gourmet-cooking magazine. Cut up an old book that is falling to pieces and make something cool out of the pages. Doodle. Seriously - doodling is a legitimate form of therapy for those of us who can't bear to put the pen aside, but find ourselves drained of words.
What I mean to say in all this is that you don't need to panic: I'm busy with a contest-piece and monetarily scheming and feel a nagging in the back of my head that says The Baby needs work and I'm neglecting this blog and many other things. Oh well. I don't have to get my tail in a knot over the fact. Inspiration has hidden for a week or two, who cares? If I've learned one thing over the course of my years as a writer, it's this:
Don't worry about your inspiration: Yeah, it might be gone; but it's too arrogant not to come back.