If you want I will include you in my homepass relay network so that you can get streetpass tags from all over the world.
All I need is the MAC address of your 3DS so that I can put it in the privacy filter. You can find it in System Settings -> Internet Settings -> Other Information -> Confirm MAC address.
Click here to email me.
Connect to the “attwifi” network next time you are near the library and you will start collecting streetpass tags.
If you would like to know how I did this here is all the information.