Yes. A few workable approaches were suggested:

• Magic Lantern: This custom firmware adds motion detection directly to supported Canon cameras, including the T2i/550D. It runs from the memory card rather than permanently replacing the camera firmware, so it’s a common way to get motion-triggered shooting without involving a webcam.
• Webcam + computer-based detection: A UVC webcam can be used with a Linux system (including a Raspberry Pi) running Motion for motion detection. When motion is detected, it can run a command that uses gPhoto2 to trigger the attached T2i.
• External trigger hardware: A CameraAxe can trigger a camera from movement and other events.

For your exact webcam-based idea, the clearest answer from the community is the Linux + Motion + gPhoto2 route. If you just want motion-triggered photos with the T2i and don’t specifically need a webcam, Magic Lantern is the simplest option mentioned.