How can I trace a cell phone number or locate it?

If you're getting harassing calls, you can file at the prosecutors office and they can subpoena the records... but beyond that, it's just not possible unless it's publicly listed and found on a reverse search: WhitePages.com - Online Directory Assistance

You might also try googling the number. If the person has entered it on a website, forum, blog, etc. it could be found.

If you own the phone and it is one that has a built in GPS tracking you can.
Many businesses are supplying these to their employees to keep track of them.

If you are talking about tracking a strangers phone, ** which I assume you are, normally you can not, but the police can track a phone to the cell tower it is using and in major cities trace it fairly close

How can l decode my mobile phone using the internet:confused:

How can I track a cell phone by using the towers