This small homebrew clears the MacFilter__ file of your 3DS which allows you to circumvent the 8h restriction for StreetPass hits.
I know there are the dev programs CecBoxTool and CecLotCheckTool which can do the same but maybe someone prefers a hombrew version over a CIA version.
If someone wants to create a better icon feel free to do so and send it to me. Source code is included in the zip file.