What is awacsd on my computer and why does an outside computer (fd00:6587:52d7:94::1) keep trying to access it? I keep blocking it with Norton Firewall, but the message keeps coming back.
That is a process that manages communications of many kinds with MobileMe. Do you have a MobileMe account? If so, quit blocking it, as you're probably interfering with some of the things you want MobileMe to be doing for you. If not, turn on your system firewall in System Preferences -> Security.
BTW, you should ditch Norton ASAP, Norton products are notorious for causing problems on Macs.