I got the phone in september 2008.about how long ago did u buy the phone?
Ok, so you're covered till september 2010
If anything happens just restore it thru itunes and bring it in for repair.
is it true though that there is a way for apple to see if you have ever jailbroken?
Not true.
Who told you that? An Apple or AT&T employee?
Its false.
One more thing if that is false are there any cons to jailbreaking besides battery life and performance?
So if I change the root password then theres no reason not to jailbreak?Even those won't be problems if you are wise about what you install and how you use it. Jailbreaking in-and-of-itself does not cause problems. Installing and using dodgy software afterwards does.
Oh, and also not taking proper precautions and security measures causes problems as well. For example, if you install OpenSSH, and you don't bother to change the default passwords for the 'root' and 'mobile' accounts, you're setting your phone up to be broken into.
-- Nathan