If you're worried about 240p/480i switching, you may want to get in on
this new line-doubler, which would be a huge step up from the cheap converters that don't process 240p correctly. It also has line-triple support for 240p content (720p output), although the result apparently isn't supported by many monitors or TVs (which is a shame because the video capture he took of it looks awesome). I also noticed this tidbit which is troubling:
I guess we'll have to wait for the reviews to know for sure.
The thing with those is that they don't upscale, so if your TV doesn't take 240p over component, you're dicked.