I did a status update on FaceBook and was surprised at the number of responses. What was it about you ask? I noted that right after I vented my dryer into the house, the temp. shot back up into the 90's.
W/i a few minutes, several people had commented on what a good idea that was to save some energy.
The principle and implementation are simple. Let the heat and humidity from the dryer help warm your house during the cold months instead of wasting it.
I have a attachment I bought from the hardware store which connects to the back of the dryer. It contains a switch to change the venting from inside to outside and a screen to catch lint/dust. I don't use the switch due to the placement of my dryer and the outside vent hole so I just remove/replace it depending on the time of year.
Another method is to have a 5 gal. bucked w/ one large hole in the middle for the tubing and a series of smaller holes around the top. Fill the bucket about 1/2 way w/ water and connect to your dryer.
I turn my heat down at night so I put in a load right before bed and/or when I get up in the morning and turn it back up. One or two loads a day keeps the humidity level of my house just about right during the winter. A dryer sheet acts just like an air freshener.
So I cut down on my utility bills and reduce my 'carbon footprint' ( :) ) at the same time while not putting myself out more than the few minutes it takes to switch the tubing twice a year. Win/Win
UPDATE: Yeah, this isn't recommended for gas driers unless you like not waking up w/ a healthy pink glow.