Hi T.,
I know it has been a while since you posted this request and hopefully things are already looking better for you. I would not immediately discount the idea of homeschooling like the last person suggested. There are a lot of merits associated with homeschooling, and having been the exact same student your son is myself (I skated by, fortunately, with great grades despite my lack of effort), homeschooling is a viable option. Check out the laws in your state (www.hslda.org - national site that can direct you to your state).
It is daunting to consider this for the first time with an almost-high-schooler. And perhaps just the idea of it will make him want to work harder at school, not to say that the idea is only worthy of being a threat...
If your son is in fact extremely intelligent and bored as everyone else so well pointed out, simply telling him to study and do homework isn't the solution. Depending on his learning abilities, he may absorb information quickly and coherently, and find it ridiculous to have to regurgitate it just to prove he knows it. In homeschooling, you have the option of testing, written reports, oral reports, and more to choose from as ways to demonstrate his knowledge. It isn't simply staying home and "playing" school, but rather is catering his educational experience to make the best opportunities for him to learn. The goal is the child, not the grade or the test.
Yes, in some segments of corporate America, there is the need to perform homework-like tasks (reports and the like) but that is seriously different than book reports and essays. You can still give him the responsibility and knowledge to be able to perform these tasks, if not moreso than the school system. In many segments, the type of knowledge you get in high school, the type of learning used in school, really doesn't equate to the job market.
In many cases, school simply proves you CAN learn, not that you did. As a succesful small business owner, I can say from experience, being able to complete homework and term papers has not directly (and I struggle to see indirect connections as well) impacted my ability to run a business. Keeping a journal that was graded has. OJT programs have. The military has. Self-led interests and subjects around which academic opportunities were planned have most directly contributed. When I was interested in marketing, entrepeneurship, business - I sought the opportunity to read and write about these things. I was never encouraged to do my repetative homework instead of these things. Not spoon-feeding me information has made me self-sufficient to learn the things I need to know to be a successful business person and mother.
If homeschool just isn't an option for you, and it isn't for everyone, consider other options - tutoring centers that will sit with him and work with him through his assignments. Go to one that focuses on making homework appear easy, manageable, and worth the small amount of effort it actually takes.
Some centers focus on "math" or "reading" and don't put the effort into instilling the habit as much as the academic subject. You want one that will enforce the habit and show your son why homework is worth it for HIM. I worked for many years at Sylvan Learning Center and some are better than others, but overall, I would recommend them. Just don't automatically discount homeschooling if it will work for you. It is a legal, viable option, that should be considered.