No, I don't believe you can. This is a security measure that requires your password every 15 minutes & prevents kids logging on to pay services & running up big bills.
Well, as is usually the case ))... there is a way if you are jailbroken. You can install the Cydia tweak "PasswordPilot." This free tweak automatically inserts your App Store password when installing or upgrading apps from the App Store.
Of course, the usual caveats apply: Be careful if you install this, as it means that anyone can buy any app from the App Store as the password is automatic.
Thanks guys, I appreciate your input here. It's really not the big a deal for me, just a minor annoyance that I would have eliminated if possible with out a hassle. I'll keep things as they are and we can consider this thread SOLVED and for me Closed.