[Arduino] water sensor

I was tinkering with the idea of water sensing with arduino. The rain sensor / water sensing kit/ water detector/ is kind of hard to come by from the Internet stores. Courtesy of Mr.ChongSP, I get to sample his water detector PCB.
Thanks!
The concept of working is the gap between the PCB routes will close when there is a water droplet run across it. Water conducts electricity.  With the appropriate pull up resistor connected with the PCB kit as per the diagram below, we could get the components up within minutes.
Quickly I hook it up with my arduino and used the "button" sample code. i.e the switch button is now my water detector. If there is water, light up the LED, and if there is none off the led......


Now, here comes the interesting part.
1. instead of the usual project of "detect rain-retrieve-laundry" type of application, can we have something more interesting????? I have at least one in mind... hehe
2. is there a way i could do away with the PCB water detector, it looks kinda out of reach to me. Sure! how about using double row male PCB header?? hehe