Imagine if your plants could call you when they are thristy. (I'm not sure I want my plants calling me). American Inventor Spot explains it this way:

Botanicalls is a project using ten plants connected to soil moisture sensors - a sensor is made of two nails and a circuit- which send the plants' information (such as moisture levels) to an arduino board which then passes the information to an Xbee network. An Xport is used to send data via PHP to a mySQL database and to Asterisk (an open-source telephone system), which then makes the phone call. When the owner picks up the phone her plant (an automated voice) will let her know how thirsty it is.

The brainchild of a group of students from NYU, their site Botanicalls, lists a number you can call to "talk" to some of the plants who have made recent requests.

Meanwhile, your ficus wants a chat and sounds pretty pissed.