[jmq]

Very useful indeed.

Does anyone know other tips or tricks? Like the Sprint 800 number that will read back your phone number from where you are calling from?

[bert]

There was a comic strip yesterday depicting an old lady who bought a cell phone so she could call it to find her misplaced pocket book.

[Sax]

Sure, for a cot and 3 hot meals a day, just dial 911 and start cursing. Repeat if necessary.

[Just another Joe]

Like the Sprint 800 number that will read back your phone number from where you are calling from?

There isn't a nationwide number for this.
For cell phones it depends on the company.
For wireline it depends on the company and the region.