Form an LLC. Not quite a corporation, but accomplishes what you are looking for. http://guides.wsj.com/small-business/starting-a-business/how...
(edit: I'd walk away from that loan, given the issue of piercing the veil I mentioned in my previous post.)
"Perhaps you mean that sometimes those extending loans to single-member LLCs require that the member co-sign the loan?" Yes.
As long of the funds from the loan are used strictly for LLC business purchases and purposes one should be able to keep the corporate veil in place. Even if the LLC defaults on the loan/debt the creditor doesn't need to pierce a corporate veil to go after your personal assets to repay the loan... they have your personal liability signature. Your corporate veil would/should still be in place for any other transactions that the LLC is a party to.
> ... if I were to try to get a loan or credit card
> (a.k.a. a line of credit) for my LLC...
> ... but most single member LLCs will require
> personal liability.