Asks about cell phone triangulation

McAfee, using his “stuffmonger” alias, posts to a private message board asking for information about how phone tracking works.

How long does it take for a phone company to triangulate a cell phone signal? With what accuracy? Is there any way to confuse/delay the system? If a cell phone is turned off, but the battery is installed, is there any way to locate the phone? Are there any brands of phones are more/less difficult to triangulate?

Answers range from useful to speculative.