Power on laptop without opening lid

From this thread :

Put it on suspend rather than off, then wake it up with a piece of semi-flexible "tonge" and insert it between the lids to press a key.

Not high tech, but effective and cheap.

Some laptops may support this through custom docks, but there is no general way to perform this.

Some laptops I've used were such that they powered on automatically when put in the dock, but not all of them. Also, every dock I've ever used had it's own power button that could be used to power on and off. Another option, if it is being used on a LAN where you have another computer connected is to set up WAKE ON LAN in the bios if it supports it and send a ping from the other computer to the laptop. A bit of a long way around and probably not worth the effort, but it could be done.