You can take tours from China across into North Korea (or by train, in theory) - but assuming you do and get your passport stamped, are there other countries that will hold this against you?
For example, if you visit Israel, certain other middle-east countries get a bit iffy about that, to the extent that I've heard people suggest you don't get Israel stamps in your passport. I'm wondering if this applies to North Korea as well, with any countries?
To clarify, I don't mean 'iffy' like America may question you about drugs if you enter from Colombia, I mean 'iffy' as in they may turn you away at the border, or worse.