Little Snitch keeps you covered
Use Little Snitch to monitor what developers of programs sends home. Then you can stop that specific traffic. More and more programs phone home with information to the software company. Sometimes it’s harmless, like checking if a newer version is available, but sometimes they also send data like serial numbers and your registration information. So is there a way for you to control what programs can do? Yes, there is! There’s an excellent program called Little Snitch that monitors all communication from applications on your Mac OS X machine and asks you if the information is allowed to be sent over the internet.
Great stuff! And you can tell the program to remember settings so you can allow regular communications to get through.