One of the recurring ideas that's been reasserting itself in my head recently is the idea of constraints being useful, and even necessary for creative work. Stewart once did an excellent presentation on how constraints can improve the results of an effort. He made a profound (to me, at least) demonstration that the difference between work and play wasn't the tasks being completed or the rewards earned, but rather the presence or absence of rules.
Games have rules, and that's what makes them fun to play. Tedium happens when there are no boundaries or limitations to mark completion, success, or progress.
Of course, thinking about working with constraints brings me back to playing with the web. There are all the limitations of doing something creative in HTML, from technical limits like browser capabilities and software distribution and user savvy, to cultural constraints like flame wars, aversion to payments, and mistrust of strangers. But there's also tremendous creativity brought on by requiring any project that wants to find a wide audience to meet a really stringent set of constraints. (You can't crash browsers, you have to be able to be bookmarked so people can pass on the link, you need to work even on slow dial-up connections.)
This came back to mind on one of hte plane flights I was on last night, as well. I ran into Dave Shea, who built the CSS Zen Garden and co-wrote its companion book. I read the book last night (I'd recommend it to people who are into that sort of thing) and what I was struck by wasn't the cleverness of all the designs that people had implemented, but rather the fact that all that creativity was unleashed by having had such tight constraints on the paths into which innovation could be channeled.
Importantly, there is something freeing about finding that constraints don't really place limits on what can be achieved. That's a bigger point than just the web, of course. There's a recurrent theme in nearly every culture that being an ascetic can lead to inner peace, of the principles that are usually grouped under the concept of "zen" in popular culture.
I'm hoping to post more about the topic, but I'm constrained by time right now and I figure I might as well obey the constraint.