Hello, I am very interested in buying one of the Canon rebel series cameras. I am confused though on what I should buy. I have been comparing the XS, XTi and XSi. From what I understand the XS is the newest of the three. But the XTi is only $50 more in some places. What is the major difference between the XTi and XS? Is it worth it to spend the extra money and buy the XSi? Are there any newer cameras coming out soon? Thanks, sorry for all the questions. I am just getting very bored with my point and shoot camera and need some advice.