In the office we say the latter. The meaning behind the term isn't posted on the site but is appropriate to answering your question: http://en.wikipedia.org/wiki/Polis

In short, Aristotle thought there was a max size to the self governing city state, so we played off of that as the goal was to create a comment system that could handle tens of thousands of opinions and stay orderly (think virtual town hall / lots of people on the bus to work responding to a mayor's question to the whole city). Email, discussion threads, comments that scroll down, etc, top out pretty well beneath that, and simple upvoting and downvoting doesn't capture groups.

While we started out in politics, we're exploring a lot of different avenues right now with our current users, including education, replacing comments on blogs, etc.

In Greek, it actually sounds more like the "lis" in "lisp" (short i):

http://vocaroo.com/i/s07xxGjtkQB1

StavrosK, I spent a moment saying both and we have been saying it your way.

We've been saying: po as in police, lis as in lisp

I have heard that a valid pronunciation of the Greek is also:

po as in hot (closer to the 'a' sound that 'o' can make) lis as in lisp

You'll have to let us know if that's right!

The "o" in "police" is long, you need a short one. The English pronunciation is what you would transliterate as "poulis" (can't write IPA on the phone, but it's a short o followed by a oo sound). In Greek, the o is as in "hot" in duration, but not in sound (not close to the "a' sound).

There's only one way to say it in Greek (the one I posted above), I suspect that the person who instructed you to pronounce it as in "hot" meant the duration. I can't think of an example of an English word with a pure "o" sound at the moment, I'm afraid. You're going to have to listen to my pronunciation above to get it right :-P "O" as in "hot" is fine, as long as you don't pronounce it too much on the "a" side.

I thought to pòlis, in Greek.

Edit: https://pol.is/5hfrym