After holding off on jail breaking for 2 years, I finally bit the bullet and jail broke my iphone 4 about 3 weeks ago. Here was my experience: 1. Jail breaking was very easy. I went to the website and just did it. I know if there are issues I will need to re-install the OS on the phone but, for me, that's not a big deal. 2. Cydia and Rock were easy to interact with...not as easy as the iTunes store, but none the less, pretty easy. 3. I downloaded MyFi and Alanaz Glass Orb(theme) from Cydia and I got My 3G from Rock. The installs went smoothly but it took some time to figure out how the software works best. 4. Tethering works. Period. And with an unlimited data plan...lucky me. 5. 'My 3G' and 3G FaceTime works. And with an unlimited data plan...lucky me. 6. The Alanaz theme is very cool. At the end of the day, it is very much worth it. I know that when the next big OS upgrade comes I will have some re-work to do once the jailbreak software is ready...yes, there will be a few week's lag behind the release and the break but that's OK.