Ran chown -R user /var and most things are broken As the title says I ran sudo chown -R user /var and now most things on my machine are broken. I've fixed some permissions manually (in /var/folders) by checking against another machine but it still freezes after 10-30 minutes of use. 

I tried to reinstall OS X but the installation hangs at a certain point and doesn't look like continuing. "Repair Permissions" runs but does not fix the problem. "Verify Disk" completes but "Repair Disk" just fails halfway through.

There are messages in the Console that look concerning but it's hard to tell which caused the freeze and harder to correlate the error message with a program or a permissions issue.

I don't have a backup or I would restore from it.

Curious about your thoughts,
Kevin
Try run this in terminal:

diskutil repairPermissions /


About DiskUtil Repair Permissions