Actually, ID isn't limited to biology; it can apply to any physical science. For example, ID in 1890 would have concluded that since flying is too complex, birds must have been created.
Alternatively, since we haven't yet been able to re-create certain elements such as diamonds, petroleum, gold, etc (without consuming more energy/material than the end result), ID also lends itself to concuding that, well, it's too darn complex, therefore it must have been created.
ID is better than a good household cleanser - it can be used in any number of ways to explain how things exist without gaining any real knowledge.
When some saw airplanes first fly, they concluded that it was impossible unless angels were holding the planes up.