Canon uses different codenames for the same camera body depending whether it is sold in North America or Europe. In Europe we have the 50D, 550D and so on, while the US has XTi (or something like that).
Most of the questions on this site just refer to the names they're familiar with, so it would be useful to have a post to refer to which can translate the names. I'm making this CW in the hope that this will be updated as new models come out.
I put together a translation table in this answer:
EOS 1100D = EOS Rebel T3 = EOS Kiss X50
EOS 1000D = EOS Rebel XS = EOS Kiss F
EOS 650D = EOS Rebel T4i = EOS Kiss X6
EOS 600D = EOS Rebel T3i = EOS Kiss X5
EOS 550D = EOS Rebel T2i = EOS Kiss X4
EOS 500D = EOS Rebel T1i = EOS Kiss X3
EOS 450D = EOS Rebel XSi = EOS Kiss X2
EOS 400D = EOS Rebel XTi = EOS Kiss X
EOS 350D = EOS Rebel XT = EOS Kiss N
EOS 300D = EOS Rebel = EOS Kiss
Wikipedia has a good breakdown of the Canon dSLR line that includes the variable names so that you can easily see. It also includes a handy comparison summary of their features.
