If you're shooting 60i, then DVFilm Atlantis is one solution. Vegas does a good conversion in the NLE as well.
If you're shooting 24p, then you basically just need to speed it up a bit so it's 25p. You can do this in After Effects by interpretting the footage as 25p, and then speeding up the audio a bit.
I've heard there's a way to do the conversion in Final Cut, but I'm not an editor and have never personally tried it. You may want to search around in the FCP forum.
