Does anyone keep a "literary sketchbook"?

An idea a writer friend shared with me....

Carry around a lined notebook or journal. Any time you are otherwise unoccupied (waiting for a bus, eating alone in a restaurant and waiting for the food, etc.) pull it out and write a paragraph that "sketches" the area where you are. Tind something interesting in your immediate vicinity and write a paragraph describing it. Then write a few paragraphs sketching a story about that something. The old man next to you on the bus bench who keeps looking up at the skies with a worried expression... what is he afraid will happen? The nicely dressed middle aged women having lunch at the next table over, chatting in low voices with heads leaning in... what are they conspiring?

Apparently this does a number of things. It is a quick practice at writing. It helps you capture a description you might want latter; I know that I've despaired of describing a sunny summer day in the middle of a Seattle winter. And it might serve as inspiration for future stories about the retired NSA agent who knows too much about our alien overlords or the cabal of women who run the Illuminati.

It sounds like a great idea, and I'm wondering if anyone else does something like this.

I carry my handheld PC everywhere... mostly I cannot read my handwriting anymore

I always have my notebook with me for class etc, but in the past I would carry a little notepad and write down stuff there too. I write down funny things, or unique dialogue etc. It's helpful.

notebooks, I'm less motivated to sketch than I was in the past.

When I have a long drive to make, I take a portable tape recorder
to make comments about things I see, stories suggested by those
sights, and babble about problems in my current literary projects.

I used a 'sketch book' to polish/practice what I viewed as my weaknesses - like description. I would take it with me and find something/someone to describe, then try several ways to describe that person or thing.

I also, in the same book, just recorded observations - like recording types of birds that were the first to return in the spring, descriptions of a day spent caring for a 3 month old baby, a unique physical characteristic I could use for my own characters, storms as well as all that comes before and after, the first snow and what it looked like - generally things that I could use to make a story or character feel real and in the now. Like you said, when you're sitting at your desk in February, swimming in sweats and blankets, listening to the rumble of your furnace trying to pump heat into your house as you look out at a blizzard, it can be hard to remember what a hot muggy day feels like. So part of the purpose in recording these things was to give me cues, as well, so I could close my eyes and be there.

I think it is a great idea as well. The reason I do it less is that my kids have grown up and I no longer have to spend time waiting for them to get out of school or finish that baseball game or take swimming lessons. I just have far fewer reasons to be away from my computer.

I've added to my sketch book, good examples of setting, place and characterization from other writers - not with any intent to plagiarize but for setting an example as well as for inspiration.

Perhaps I should make a weekly date with my sketch book and take it to a park or coffee shop or some other interesting venue for an hour or two.

I look at everything and try to think of things I need to know about this or that. After awhile the questions start to pile up. I guess the only bad thing about that is the fact that I don't have them all answered yet.