While some folks use these "photo-a-day" resolutions as motivators, like diet plans, most such initiatives end at about the same time as resolution diets. The most common cause of these plans' death; imaginative anemia. The p-a-d plan quickly just becomes a drag, like a 5th grade school assignment, for many people.
But don't give up yet, James. It's not even the end of January! Remember, My off-the-cuff suggestions, in no particular order, for you to consider.
Re: your egg...There is something momentarily captivating about such a perfect, simple form. Work the light and work the camera angles. You don't need expensive strobes. Work with different fills, with reflective surfaces,....and on an on. There is a tremendous amount for a photographer to learn from such a simple subject. Who cares about repetition?! This is YOUR learning medium, a private journey of exploration. Hell, I'd spend a month just on eggs! (That's not a bad idea.)
My friend, and a wonderful photographer,
John Caruso has also embarked on a photo-a-day campaign for 2009. John is an executive with the Anti-Cruelty Society of Chicago, so you will see frequent 4-legged subjects in his work. But he has one of the best eyes I've seen, amateur or professional, and he may provide you with inspiration.