If you take a photo, you can quickly note down where, when, why, what... the details that you'll quickly forget.
If the weather is interesting describe it - it could come in useful in a story sometime.
If you have a brilliant idea - jot it down - a scrapbook layout, an idea for a plot, a memory that's fleeting.
I have a notebook by my bed as well - vital for captuiring those middle of the night or just-dropping-off-to-sleep thoughts - otherwise you NEVER remember them in the morning!
So it's not so much a writing or scrapbooking journalling prompt today as a task - get yourself a notebook. If you're really creative, make or alter one...
For some inspiration check out Clareyfairy's notebook on Flickr. She includes ribbon strings to use as page markers so I know where to find all my important information. What a brilliant idea!
Photo by Dano on Flickr