Service Light

I was driving my vehicle down the road. I looked down to find the light reading "service engine soon" was illuminated. I frantically phoned my husband and inquired to the projected meaning of said light. He assured me not to worry. He stated the service station where we had most recently gotten an oil change had not reset it and that it was not a problem. I felt better but it got me thinking.
Wouldn't it be nice if people came with a service light? I can think of countless applications. Can't You?

Feel free to pontificate. (its the only way) lol