Site should be working ~95% now. We know there are still a few posting issues. Please report any errors to moot@4chan.org.
1. Remove all entries for 4chan servers in your hosts file (if you've edited it). Windows users can find this at "%SystemRoot%\system32\drivers\etc\hosts" and Mac/*nix at "/etc/hosts". How do I edit my hosts file?
2. Clear your DNS cache. Windows users enter "ipconfig /flushdns" at your command prompt (be sure to run it as an administrator). Mac users enter "dscacheutil -flushcache" at your Terminal window. *nix varies, but see here.
3. Clear your browser cache and cookies. This varies per browser but should be pretty straight forward.
If you run an archive and are having trouble running your script, e-mail me.
And as always, follow @4chan and @moot on Twitter for updates, and visit status.4chan.org during downtime.