3DS tinkerer extraordinaire Jordan Rabet, aka smea, has (with a little help) found a really easy way for Nintendo 3DS owners to get around the company's region-locking.
Previous attempts at breaking down Nintendo's region restrictions have required buying certain games and the installation of custom firmware, but this new method — called tubehax — is much easier; it still involves using custom firmware, but the installation is quick and painless, as it involves nothing more than installing a few files on your SD card, changing your system's DNS setting, and then firing up the YouTube app.
This video shows how to use the exploit to install the custom firmware needed to unlock region restrictions, but there are more detailed instructions here.
If you're thinking of trying it out, note that there are some catches: namely, that you won't be able to access the eShop so long as you've got the custom firmware enabled, so if you want to play games from other regions, you'll need the cart. The good news (if that worries you) is that tubehax will only remain in operation so long as you've got your 3DS pointed towards a specific DNS. Reset that and your 3DS will return to normal.
Nintendo will obviously be concerned about the potential for 3DS piracy, but smea says that's not an issue with the way this particular firmware runs. From the exploit's homepage:
Does this let me run roms ?
No. These exploits run strictly in userland, meaning that we do not have full control over the console, and therefore cannot run pirated software. That being said, we have the same amount of access as regular apps and games to the console's hardware, and so we can make some kickass homebrew!
In addition to running homebrew (and by extension emulators, which Nintendo would also be pissed about), tubehax also lets you install custom 3DS themes.