Nice posts everyone.
As for this comment:
"Just wanted to add, screen windows keep pets in and pests out"
I assume since no one else in this entire thread mentioned windows, this is a suggested solution to my problem. How exactly though, will window screen stop male cats from spraying directly into my house via my window screen? LOL. You leave the window open an inch, and BAM, a male has put his butt to the window and sprayed inside all over whatever is near the window. So um, no window "screen" doesn't help as spray goes right through it. But yeah thanks for the idea???? I guess I have to continue keeping my windows closed so someones cute kitty can have his nights outside.
Our new solution to our personal cat problem is setting up live traps. Find a cat and it goes to the SPCA. If the owner didn't pay to have a microchip, that's too bad.
Seamus Haley's comments on the issue are exactly my thoughts as well.