Yeah anything internet, serial code and infrared is region locked.
Only local wireless is region free.
What's this themehax? Should I bother? Lol
And hmm, Taiwanese movie events.
If you're on a newer firmware, Themehax would be unavailable to you. There are a couple entrypoints for *hax that work on the newer firmware though. However, I think they all require a physical game. Namely Cubic Ninja, OoT3D or I believe Smash. I think Smash requires extra trouble though.
When you have a working entry point, you can launch the Homebrew Launcher and do various things. One of those is run games regionfree and even spoof region. You can also take screenshots in any game if you run it through the Homebrew Launcher, so that's neat if there's something in Pokemon to show off, for example.
It also enables homebrew, obviously, and can let you do some neat stuff in general.
Edit: Oh right, and as the conversation stated, thanks to the ability to go region free(and the ability to spoof regions) you can grab Internet events on other region cartridges. Sadly, it doesn't seem possible to use the region spoofing to get Japanese serial code events, it acts as though the game isn't using the latest patch and doesn't let you go through =( But I have heard of foreign players being able to use the spoof to grab the Wi-Fi version of Zoroark from NA, for example.
Edit2: It doesn't actually require a physical copy, I should clarify. I believe Cubic Ninja was pulled from the eShop so there's that. I think OoT3D works with a digital copy but I'm not sure. And I have no clue about the Smash exploit in general lol. It's really easy to set up *hax on physical OoT3D with Powersaves, but it does have an unfortunate side-effect of requiring you replace your save with one that exists only to initiate the Homebrew Launcher.