I just came to know how Google Adsense detects invalid clicks. I hope this is the very good information to avoid your Adsense websites from invalid clicks.
IP Address:
If the Adsense click is originated from the same IP Address as the one used for accessing your Adsense account, your account is flagged.
Cookies:
Most home users do not [...]

Have you ever noticed this pop up ? When you enter any password with Login ID at your Favorite Social bookmarking sites like Orkut, FaceBook , Myspace Or e-mail sites Like Gmail, Yahoo, Rediff, Or even highly secure sites like Paypal (Paypal never allow Firefox or any other browser to remember passwords)

Actually this pop up [...]

These are the few Symptomes of Google Mania
Number 10 :

Your kids still believe the Googlebot is bringing the Christmas presents. (ONLY If you have Kids)
Number 9 :
When someone asks “How are you?” you mouse-click in mid-air at them and say “I’m feeling lucky.”
Number 8 :
You shout at the librarian when she takes more than a [...]