I recently purchased an invisible shield for my iPhone 3gs, but now I’m second guessing it.   I bought a Case Mate invisible shield but it was difficult to install and very stressful.   However, when it was finished I enjoyed the protection it provides. If you have an iPhone 4 it will not solve the reception issue because it only covers the front and back.   More protection is  never a bad idea ,but you can get more for $20.   Let me know if you would buy an invisible shield, or if you have one leave a quick comment on your experiences.

Zane