Well, if you're like a lot of people in Plymouth, you've gotten that cell phone number email today. Most of the info is just not true.
Here's info from The Federal Trade Commission's (Do Not Call registry) site:
You may place your personal cell phone number on the National Do Not Call Registry. The registry has accepted cell phone numbers since it opened for registrations in June 2003. There is no deadline to register a home or cell phone number on the Registry.
You may have received an email telling you that your cell phone is about to be assaulted by telemarketing calls as a result of a new cell phone number database; however, that is not the case. Federal Communications Commission regulations prohibit telemarketers from using automated dialers to call cell phone numbers."
If you want to, you can register online, but as it mentions, it's not necessary.