This instructable will show you how to block that anoying bleeping interference with radios and speakers when your cellphone connets to the mothership or that rare time when someone is actually calling you.
You will need:
2 cell phones (one to test with and one that causes interfernce)
1 9 inch piece of foil (tear off 9 inchs of foil)
a flat surface to fold foil.
Parental Guidance if needed.
Step 1: Folding the Foil
Place the 9 inch piece of foil on the table.
Place your phone on top of the foil, near the top edge.
Now fold the foil in the middle by bringing the bottom of the foil over the phone. Meet the two jagged edges together and crease the new bottom edge.
See diagram (fold on red dotted line)
Step 2: Making Side Folds
After making the main fold in step 1 we will fold the sides down so the phone doesn't fall out. Note: The phone should be still sandwiched in the middle.
FOLD on first red outside red line. Then FOLD again. Repeat for other end.
Step 3: Finished.
In my tests the foil is sufficient enough to block the signals to your phone that causes interference with stereo equipment and computer speakers. It blocks the signals so well that when someone tries to call you they get a message that you are unavailable! Your phone doesn't even ring! Its like your phone is not even on!
A small wallet sized one may block RFID chips in credit cards/Drivers License
Although I am not condoning illegal activity a larger version can be made to fit a libraray book. It might be enough to block the scanners from reading the RFID tags affixed to library books incase you wanted to take home a reference book.