I have some pictures I accidentally took on the internal memory of my Canon Rebel t2i.. How do I retrieve them? Thanks in advance!

If you connect the USB cable from your computer directly to your camera (instead of taking out the memory card and putting it into a card reader), you should be able to retrieve those pictures

There is no "Internal Memory" on a Canon Rebel. However you have probably discovered that you can "Shoot without a card" and they appear on your camera in review mode. When you go to connect your camera the photos are nowhere to be found. I have found a solution. It kept me up all night trying to figure out how to get those photos off the camera instead of losing them forever. About 1:00am it came to me, I connected the camera to my printer via Pictbridge and printed the photos. I then scanned them to my computer. This is not the ideal solution, but if you have photos that are special this is a work-around. It doesn't help if you planned on editing the photos but at least you have copies that are decent quality. The Canon has options for print quality when connected to Pictbridge.