Here are any phone tricks I have found. Use them at your own risk! <phone number> means that's where you insert their phone number.

*67<phone number>*

Block Caller ID

*69*

Redial the person who *67'ed you (Last Call Return)

(Not many people know about it)

 *57

 Verizon Unlawful Call Center (Costs $1 to use) (Malicious Caller Identification)

*77 (on) *87 (off)

Anonymous Call Rejection (blocks anonymous calls)

(408)-236-2060*

Rejection Hotline

More phone numbers can be found at RejectionHotline.com

911-<any four numbers>*

Calls 911 immediately when you type it in

*Has been tested. (Do not actually type the star in.)