[anthonyh4429]

Here's a summary of the differences, per dpreview.com:* 10.1 megapixel CMOS sensor with improved microlens array, fill factor and lower noise * EOS Integrated Cleaning System * Anti-static coatings on sensor surfaces plus anti-dust materials in the camera body * Separate low pass filter with ultra-sonic vibration * Software based dust mapping / removal * Nine point Auto Focus sensor (same as EOS 30D) with F2.8 support * Continuous shooting burst up to 27 JPEG and 10 RAW images * Single large, bright, 2.5" LCD monitor with 160° viewing angles (horizontal and vertical) * Camera settings and adjustment on LCD monitor * Proximity sensor below viewfinder eyepiece to disable the LCD during composition * New viewfinder view includes 9 AF points as well as EOS 30D style status bar * Picture Styles, larger range of image parameter adjustment (same as EOS 30D) * Improved user interface * Image magnification available in record review * Histogram available as brightness (Luminance) or RGB (Red, Green, Blue) * Three settings for long exposure noise reduction (adds Auto option) * Auto rotation with three options (not recorded, record don't rotate, record and rotate) * Additional custom functions (magnified view in record review, LCD display at power on) * Up to 9999 images per folder on storage card * Automatic storage of setting adjustments (no longer requires a press of the SET button) * Improved print / share / direct print features As you can see, most of the above improvements, other than the sensor itself and back LCD, appear to be more in the user interface. Really, the $150 goes more towards:1) a larger sensor and better AF2) the integrated cleaning system3) the bigger LCDHere's a visual list:http://www.dpreview.com/reviews/canoneos400d/page3.aspSo, essentially, I think you should consider whether these improvements are worth $150 to you. I think the bigger LCD and better AF are worth it, if you're not on a tight budget and your dad is willing to buy it. The sensor size--not so big a deal. So: get the XTi. You won't regret it. And it's better than wondering if you should have gotten the other camera (which you would do if you got the XT).Other things to get: I always recommend a backup battery and get a lens cleaning kit. When you can afford it, get the speedlight. I'm not a big fan of UV filters; the sensor is already UV filtered, and I use a lens cap and lens hood for protecting the lens. Salesmen will always try to push filters on you for "protection." See this website so you know why you're buying a filter:http://www.bythom.com/filters.htmYou already know to take some classes, so the best advice: have fun!