Three sites that restrict text by 1) number of words, 2) number of questions, or 3) amount of space.

Panopticist
Panopticist limits the word count on its sidebar link roll. Check out the haiku-like “five five-word links.”

Tull’s Ian Anderson loves cats!

The horror of overcompressed music.

Bronson Pinchot’s now a freemason.

The aesthetics of wind farms.

Mike Davis on “horrific mega-slums.”

SuprGlu
Instead of offering typical bios, SuprGlu conducts interviews with users customers in a “three questions, three answers” format (example).

3. 3 things you’d bring with you to an island, for a week?
That’s funny, I didn’t even know this Island question was next. For a week, let’s see. I think I’d definitely bring my wife. Now this is always the tricky part. If I bring my laptop or ipod does the battery magically stay charged for the week or am I just out of luck. If it stays charged then I bring my laptop as one item. If no magic batteries exist then I guess I bring my pet unicorn and a sci-fi anthology. The unicorn is cool right?

Similar: Guy Kawasaki’s “Ten Questions With…” interviews, the “5 Questions” bit Craig Kilborn used to do at The Daily Show, and FiveQs (the same five questions are asked to various “inspirational” people).

37signals
Columns present a challenge for online layouts when text runs too long or short. When we recently redesigned our marketing sites, we decided to embrace space restraints and shape our text so it shows up in matched columns which end at the same point (Basecamp shown below, you can also see at Backpack and Campfire sites).

BC

It means shaving a few words here and there but that’s all part of the challenge. You’ve just got to make it work.

Related: Embrace Constraints [Getting Real]