I am writing to ask which is your average memory usage of the Iphone 3GS. Since I have found mine at 75% and rebooted, now it is averaging 45%. It is not jailbroken, because it is one of the new models, so it can't be multitasking. I am suspecting my Iphone 3GS is not working as it should because it slows down a lot in less than a weeks use. I had one of the former 3GS and was jailbroken and ran fine.