There is no way to do what the OP is trying to accomplish. It was the single greatest disappointment I experienced when I purchased the iPad as a family device. The iOS heritage as a phone OS combined with Apple's business strategy effectively forecloses the possibility of convenient sharing of an iPad.
BTW, considering that iPad 2's now constitute the majority of all iPads, suggesting that solutions lie in jailbreaking the iPad (when it is not possible to do so for almost all iPad 2's or even for an iPad 1 with an OS version later than three generations behind the current release) is hardly a reasonable workaround for the problem.