I found a thread specific to the Securifi key fob here, but it looks like they have many sensors that utilize Zigbee. I just found their water sensor for $25 on Amazon.
[quote]Compatible with ZigBee Products
Protects Home or Property from Water Damage
Built-in Tamper Switch for Additional Protection
Slim, Weather-Resistant Design
Radio Frequency 2.4GHz RF
Communication Range Open Air: 100M (Max.)
ZigBee Channel 11, 14, 15, 19, 20, 24, 25
Switch Tamper Tamper Switch x 1
Water Sensor Cable Length 3M (10 ft)
LED Indicator Green LED x 1
RF Supervision Interval 60 Mins[/quote]
No integration as far as I know yet. If someone does get it figured out, I have 2 motion sensors and a keyfob that I would love to use with SmartThings.