Have you ever wanted to open iChat or Adium to check a chat log, account setting, or other information, but didn't want to connect to your instant messaging services? Rob Griffiths at Macworld offers a great tip on how you can easily do this, and it won't annoy your online buddies with incessant signing on/off.
Before clicking on iChat or Adium, hold down the shift key and continue holding it until the application launches. When the app opens, none of your accounts will be logged in. You can then manually login to individual accounts as necessary. Try it and see!