If you're trying to read your blogs while your kid plays next to you on the floor of your office, she'll love it if you let her play with the phone. However, just unplugging the handset won't cut it. She will still be able to turn on the speaker phone, press the buttons, and get a response.
Then, when you hear a small, tinny voice coming out of the phone speaking Chinese, and you desperately hope she has only called Chinatown, you will quickly check the Caller ID and discover that, no, she didn't call Chinatown, she called China.
After that, you will learn to unplug the phone at the base, not the handset.