To the OP & others who have suggested based on just the Specs,
Go for either the 450D or the 1000D only.
Do NOT even think about the 500D. The 500D is just Bull-shit of an SLR. 15MP cramped into the small Sensor means more Noise and degraded IQ. Also, max. usable ISO also is affected due to the Noise Issues. Only 'L Glass' will be able to satisfactorily produce good Images out of it. (Pricey). Forget the Kits lens like 18-55, even a decent lens like 28-105 or 55-250 wouldn't produce acceptable Images on the 500D. What u'll get is just Blurry Images at Pixel level. Images may be appear Good on a 15" - 22" Screen, but pixel peep it and u'll get just Blur. 15MP also means much less Buffer (Frame Rate) & much less Image Storing Capacity. HD (720p) Video will only require Gigas and Gigas of HDD Space. And thats not what an SLR is made for.
So, whats the Conclusion? Go for the 1000D or the 450D ! Why?
-- The Bang for the bucks Consumer SLRs at present.
-- Exceptionally Good IQ.
-- Lesser Noise compared to 500D.
-- Much Higher usable ISO Settings.
-- Decent Frame Rate.