If you use iChat for work, you may want to record your iChat sessions for later recall. You can always save any individual session using the "File -> Save a Copy As" commands. If you want to do it more systematically, go to "iChat -> Preferences -> Messages" and check the box "Automatically save chat transcripts" and select a folder. Now every chat session will be saved to disk. To browse or search those transcripts, there's a handy little program called Logorrhea from Spiny.com that does a great job of letting you find and review your past chats. Even better, its free.