From the link:

1. Fine if you're in Europe. Doesn't work throughout the world.

2. Myth.

3. Something like this might work on Nokia cell phones only, but it depends on cell phone and carrier. Hardly applicable to all cell phone carriers or makes, so largely a myth.

4. If you bought your cell phone from a cellular carrier like Sprint or Verizon, they already have your serial number. While it's good to keep your serial number written down somewhere, this isn't something new or special, is it?

5. This has been known and working on any phone (not just cell phones) for years -- I've been using free-411 for at least 2 years. Local phone companies on your land line also often charge for directory assistance calls after the first 2, so it (and the recently announced free Google 411 service) are good things to keep handy.

So yes, some of these are myths and don't work. Some are real, but aren't unique or new to cell phones. Others are good info to have, depending upon your phone and carrier.

DocJohn