The unfortunately named USB Phonebook Flasher is a great gizmo; one that I wish I'd had a few months ago when my long-service LG croaked on me.
We've all been there, right? You've built up a phonebook of hundreds of contacts stored in your mobile, but you have no way of backing them up. If you're a Cingular customer, you can move your numbers to your SIM card, but good luck trying to decipher which number is Bob's mobile number, which one is his office number, and which one is his home number. If you're a Verizon customer, you're completely out of luck.
Then your phone dies. Getting a new phone is easy enough. The hard part is spending an entire night plugging all your contacts into the new phonebook or, worse yet, emailing everyone you've ever met to beg for their phone numbers so you can plug them in.
With the aforementioned USB Phonebook Flasher, you can periodically take backups of your mobile's phone book, plug the gadget into your USB port, and transfer it, intact, to your PC. Then, when your phone dies, you can reverse the process to the new phone and, voila, you're back in business.