Segnalo questo "hack" (relativamente semplice) per attivare una stazione di relay del Nintendo Streetpass capace di collegarsi con tutto il mondo.
Descrizione tecnica presa da GBA t e m p . n e t (non posto il link diretto perche' e' un sito "a rischio")
For those more familiar with networks the idea seems to be that Nintendo use the mac address of the access point to note what goes. Spoof the mac address and the SSID to match that of someone else and you can get a streetpass like you were there was well.
A bit more generally this does not require special hardware but the setup might be a struggle for those without much extra network hardware sitting around, fortunately devices like the raspberry pi, android phones and laptops where you have wired network you can use for this are all possibilities.
The idea is you set up an access point (known SSIDs) with the mac address of the wireless part set (hard to do in a lot of commercial routers hence the need for wireless cards or the other options) to the same one as someone else somewhere else in the world. The 3ds then sends what it thinks is the mac address off to Nintendo's server which then sends your mii data to the next people to go to that access point. Mac addresses should be unique to each device and are available as part of standard local network protocols (no need for special software) so Nintendo presumably thought it would be a good method to make sure the Mii data got where it should be going. By setting up a clone it is then fairly obvious to see how you can send it halfway around the world.
Windows versions post windows XP (nice tool that SignZ mentioned) are posing a problem for some and as mentioned there are not so many home routers that have the option to change it (things like DD-wrt being the main exception) so you may end up downloading a linux liveCD.
Nintendo may attempt some form of patching or blacklisting in the future but right now it matters little to them so have at it if you want such things. Again it is not a major hack and for many it will seem like cheating at solitaire but we at GBAtemp offer congratulations and thanks to those that put in the spadework to have this happen.