Anti-signal phone case is cheap, if unnecessary
You can also save $6 and turn the phone off.
I've never understood why a cell phone signal-blocking handset case is needed when all one has to do is simply switch off the darn phone. But if you really must have one, just to show your geek mates you've something they don't (for good reason), check out this $6.38 option. It's available at the irresistible DealExtreme--an online retailer that BoingBoing accurately sums up as a seller of "cheap Chinese crap you were never sure you needed"--with free worldwide shipping thrown in.
However, the "leather" in the casing looks dodgy at best. And if you do
stupidly use the signal-blocking case, take heed that your cell phone will be working doubly hard to get a signal and, naturally, draining the power cell doubly fast. Which means that when you dislodge your handset to make a call, it might be deader than a dodo. Alternatively, you can save yourself the $6 and invest in some low-tech tin foil which similarly deflects those signals.
(Source: Crave Asia)