I cracked my iPhone four. What's the best/cheapest way to get it fixed?

I have the worst luck with electronics. I always drop them or break them no matter how careful I'm being. Last year my ipod, I dropped it on the bathroom floor and it's actual pixels cracked on the inside of the iPod, and I had a warranty with apple for the first two years, but they sent it back. They said it had water damage, and refused to repair it. Which was complete BS but that's another story.

Now I have an iphone 4 that I just got in early June. It fell out of my coat pocket the other day on the floor. Luckily this time only the back glass shattered, but it shattered a lot, and the phone works fine but it's extremely annoying having it there. I've being using a case to hide it from my mother because she says I never take care of things and I promised her if she bought my an iphone I'd take good care of it. I'm getting a job soon, so soon I'll have money of my own, and the plan at the moment is to get it repaired without her knowing anything ever happened to it. How would I go about that? What's the cheapest way to get it repaired and where do you suggest I do so? I have a Rogers in town, and "The source" among a few other electronic device-selling places that would maybe be able to. Anybody else ever have similar experiences?

Added (1). Preferably alternatives to apple. I really don't like them.

Thats exactly why iphone 5 changed to that light aluminum material… To prevent it from cracking when dropped. The bottom line is if you can't take care of something then you deserve to break it. Kind of like people who complain electronics don't work when dropped in water.

Only the back glass? A piece of cake and you can simply fix it by your self with this video: http://www.etradesupply.com/video/index/view?id=16/
for the back glass, you can see here with mutiple choices http://www.etradesupply.com/apple/iphone/apple-iphone-4-at-t.html

Don't get a iphone then. The screen is made out of glass and not made for you