Some time ago I posted a message about how driving on wet pavement with cruise control engaged is dangerous. Someone just sent me that warning again and I thought with fall and winter weather approaching, a reminder might be in order. Below is the information I found on www.truthorfiction.com
(truthorfiction.com is one of the sites I use regularly to check out some of the messages that are forwarded to me. Very often the message is fiction. You may want to bookmark the site for your own use.)

Here's what they say about that particular "forward" message:

Don't Use Cruise Control when Driving in the Rain-Truth!
bullet Summary of the eRumor
A warning from a driver who lost control of his or her car during slippery conditions and was told by a law officer that cruise control should never be used when it is raining.
The Truth-
We checked with the departments of transportation for Minnesota, Wisconsin, and Washington State as well as visiting several websites of other states and the consensus is clear: Don't use cruise control during winter conditions such as when it is snowing or icy or under other slippery conditions such as when it is raining.

The comments and warnings we found were:

...The cruise control is designed for normal road conditions. It doesn't know when the pavement is slippery. Under slick conditions, you need to be in complete control and monitoring road conditions. You're more likely to notice hydroplaning if you are not relying on the cruise control.
...With some cars, it is possible that the wheels will actually spin faster when the cruise control is on and the car hits a slippery spot. When the tires make contact with firm road again, the car can skid or lose control.
...On most cars, the cruise control is disengaged by tapping on the brake. In an emergency, this adds a fraction of a second to your response time as well as the risk of the braking action itself causing a loss of control on a slippery road.