So currently purchased an AlienWare M11X and i love it so when i went to install Oblivion onto it i realized that i dont have a DVD-ROM drive... I dont want to have to go and spend 50 bucks on an external dvd-rom drive so is there any other way I can install it?

Looking at the model of the AlienWare laptop you bought, there may not be many other options. One of the other ones is buying Oblivion (again) http://store.steampowered.com/search/?snr=1_4_4__12&term=Oblivion for ~$25.

How can you have a computer without having a DVD-ROM, or some similar input device? That's like buying a car with only three wheels. You're going to need some sort of drive at some point, not every game/program can be obtained from an online source. So you may as well just buck up and go buy one.