Over on the excellent HPPodcraft message boards, a member named Parralaxicality kicked off a thread called "You know you've been reading too much Lovecraft when..." with this great Top 10 list. When last I looked at the discussion there were more than 40 entries, so head over there and take a look. Meanwhile, here's how it all started:
1. You tell your sweetheart that her eyes are eldritch
2. You quit your six figure job at CERN for fear of opening up terrifying vistas of reality.
3. You refuse to leave home when the moon is gibbous.
4. You demand that your national library grant you access to its copy of the Necronomicon.
5. You shout out in the middle of a church service that the Old Ones will soon return, shouting and killing and revelling in joy, and all the Earth will flame with a Holocaust of ecstasy and freedom.
6. You blame the poor quality of your shoes on the degenerate Asiatics who manufactured them.
7. You develop an uneasy attraction to fish and white gorillas.
8. You seal yourself up in your house, block out the windows and refuse to look at yourself in a mirror.
9. You refuse to watch Blade Runner or Aliens because they feature trapezihedral buildings.
10. When a contractor informs you that your house is subsiding, you demand he dig until he finds the temple causing it.