This was something I came up with during our weather unit. I wanted students to track the weather for about 10 days and I developed this weather journal (using the Publisher catalog template).
The first two pages were general weather map and symbol information. The remaining pages all looked the same. At the start of each class I would put today's weather map and ten day forecast on the interactive whiteboard from http://www.weather.com/ and have a couple of students go outside to check the cloud cover and type, wind speed, and I started having them read and record the barometer.
I liked the journal within the journal idea and will use it again when we start our composting project. I wouldn't do it for more then 10 days. I still have students rotate the weather job in the morning and they post the weather in the hall (I blew up the journal page above to poster size and laminated it..students plug in the information). I think next year I will have the last pages in the journal involving graphing so that students can graph the high and low temperatures, how many sunny vs. cloudy days, the barometer reading (which was really hard to read for all of us...next year I think I might invest in a digital barometer).
I also like the idea of a moon journal, where students color in the phase of the moon for a month. I didn't think of that while we were studying the moon this year but I will definitely make one next year.