It's actually a huge plus for me if the company takes the time to put a novel programming puzzle in the post. It says a few things: 1. this wasn't posted by a recruiter or somebody clueless in h.r. 2. engineers at this company still care about hiring 3. a lot of buzzword bombing b.s. artists aren't going to be applying 4. the company recognizes that raw aptitude is more important than bullet list bingo In other words…
One of the things I learned nearly 20 years ago is that it sucks to work in shops where the engineers are arrogant, because the more arrogant the less likely any good engineering is tolerated. These kinds of puzzles communicate arrogance to me. They say "We're more interested in excluding you based on a trick question than in getting to know you".
For example, the puzzle in this ad is a good one: http://newyork.craigslist.org/mnh/sof/1927765905.html