I agree with you that the addition of a search function would be ideal. There's no doubt about it.
In the meantime, I might suggest that you consider how you name and organize your course's content. In my classes, I strive to be very meticulous about how I label every page, assignment, discussion, and quiz. I also organize all of the course content in weekly modules. Lastly, I have created Assignment Groups with similar items. The more thoroughly you develop a system, the easier it will be to find the content you are searching for.
Again, I agree that a having a search function would be ideal, but you might find other ways to keep your course content in order and easy to access.