I'm just curious.

I bought a .us name on GoDaddy, and immediately went into my reseller Plesk account and setup the domain (just a forward in this case).

I got a proper DNS response in about 5 minutes! How could it be so fast? It usually takes days with .com and .org.

What's different about .us names that this happens?

JivaGo

http://www.webhostingtalk.com/showthread.php?s=&threadid=45702&highlight=.biz+dns