Is there such a thing as playing a video at 25/50 instead of 24/48 on a monitor incapable of a multiple of 24/48 (basically video slightly sped up, and audio probably resampled to match), but capable of 25/50, on a PC? Would it have noticeable effects in practice?.
What you're describing is how film content used to be sped up for PAL TVs and DVDs. The 4% speedup caused a shift in pitch (this was before it was easy to restore pitch on sped up sound), but was otherwise the best solution at the time for 50 Hz displays.
Reclock will do this (and correct the audio, I believe), but I've never used it.
Wind, Sand and Stars.