Consider whether or not Mike Gravel will still be around by the NY primaries (which are...?) as his ads alone are the worth voting for.
Even if you don't register it is a pretty self-satisfied thing you are doing given your reasons - after all, how many will affected by your "protest", a grandiose term here.
As you are annoyed at the United States government then joining a third party (and ergo voting for it...) or plotting a marxist coup in your garage are two ways of doing something about it..
I don't think Gravel made the NY ballot so I'd have to write him in. I may not make the primary deadline here anyway, the law is weird. I can't file the form to register until the year I turn 18 (which is, 2008, so I can't file the form to vote until 1/1/08) but the deadline to register to be able to vote in the primary might have already passed. so although I'm eligible in one sense (will be 18 by 11/04/08) I can't take advantage of it.
Are you sure you have your state law correct? You can still sign a registration form when you're 17. I did. You just certify that you will be 18 before election day. Here (and in most states) the law is that you can register any time before the next declared election and you're copacetic.