How about something I call as "analog processing". To achieve a look what some call as "vintage" or "lomography" straight out of the camera, it requires few things:
1) Bad lens, which means something like plastic lens or anything that gives a "soft" or almost slightly "out of focus" look. One can for example shoot through a smudged and scratched glass.
2) Vignetting, which can be achieved in numerous ways. One is to shoot through a hole in a white handkerchief to get a blurred and washed out vignetting (see the example). Or dark vignetting, which can be achieved for example lighting the scene with strong spotlight that does not lit the whole scene evenly (the center becomes lit slightly more than edges).
3) Intentional "bad photography", which can mean things like seen on your example shots: flash used and strong shadow casts on the wall, and making somewhat "bad compositions".
4) Intentional bad exposure, which can be for example overexposure or underexposure.
5) Tampering the white balance, which means you in purpose use wrong white balance preset to get for example cyan tint. I don't know about Canon Rebel, but on my Canon camera I can change the tone rather radically.
Here's an example on "soft vignetting". I took the shot with a telescopic lens, and through a brightly lit hole held close to the lens: