You don't know what a wire transfer is? Are you just being sarcastic or what? How do you fund your paypal account if you don't have a bank account/credit card? MtGox accept cash deposits to their USA bank if I'm not mistaken.
https://mtgox.com/users/addFundsIt's pretty easy to deposit some cash into MtGox's USA chase bank account. It's easy and fast. but you have to trust MtGox with your personal information as a verified MtGox account is required to do so, according to the site.
You could try to find someone trustworthy on these forums who would sell you bitcoins for cash in person, or by cash in the mail. That is probably the safest and most secure way to go about it.