I have a solution that is working perfectly. Systems freezes many times a day and also waking up from sleep, sometimes on reboot. Computer would allow cursor movement, but nothing else worked at all, no pull down menus, no programs, no file access, no clock, even the force-quit command didn't work. Detailed solution as follows:
On a Mac OS 10.8.3, iMac, 3T drive. Had same problem, thinking it was internet/safari related, tried different browsers which helped for a while, but then the problem of freezing kept happening.
Freezing also became more frequent and to the point every single time waking up from sleep would cause it to freeze, forcing a reboot. It would also freeze using many other applications. Went through all the forums and tried just about everything posted and to no avail.
My solution, after systematic diagnosing, was to run DiskWarrior 4.4, though I'm sure other versions would work as well. Standard rebuilding of the directory did not completely cure the problem, freezing kept happening several times a day and was getting worse. I then repaired disk permissions, which can be done from the standard Disk Utility app in your Utilities folder.
Freezing still happened.
I then used the Check All Files & Folders diagnostic in DiskWarrior and it came up with a bunch of errors in files that had resource headers that were damaged and could not be repaired, these being several large Word files pertaining to my novel. I left those alone for the time being, planning on copying the file information and deleting the offending files later.
The next problem on the list were several data.plist files. DiskWarrior identified these as having "Detected that Property List data is damaged and cannot be repaired."
These were within .graffle files (from the originator program OmniGraffle). I opened the files, copied out their information into new documents, and then deleted the damaged files containing the data.plist (data.plist can be found using: right-click/Show Package Contents on certain document files and apps.)
DiskWarrior also showed Property List data was damaged in Library/Cookies. I removed the file from that location, and then later deleted the file after the system created a new one. I had every suspicion this was the main culprit.
One other file's data.plist was also damaged, the com.apple.appstore.plist. I moved this file to another location, ran the app store program to make sure everything was still working (it created a new plist file after running), and then deleted the file.
I have since, even with the Word files still damaged and on my drive, had no, I repeat happily: no system freezes since doing that. Waking up the computer from sleep, which normally made me cringe, produced no freezing.
Eight days and still going completely freeze free, never shutting the computer down, but letting it sleep. Tested reboots as well and it works perfectly.
I hope this solution helps most of you ou there who are having system freezes. Nothing more frustrating when working on a novel, or editing video, than having system lockups.