Help Phone locked up

[t12b25]

Hi everybody, I was sending a text earlier, and my phone completely locked up on me. I hit the multitasking key, did nothing. I tried to pull down the notification bar, did nothing. I had to hold down the power button until the phone restarted. Is this normal, or something that I should worry about?. Should I get a backup phone just in case?. Suggestions, ideas?. Thank you all for the help,
Anthony.

 

[codesplice]

Is this the first time that it's happened, or has it become a habit? If an isolated incident, I wouldn't worry about it too terribly much. If it starts happening more frequently we can walk through some basic troubleshooting to try and isolate the culprit, but that's probably not worth doing if you can't reproduce the hung state.