You can use Twixtor to go from 24 to 25P if you want... but 24P or 25P to 30P or 60i :: That technique has a lot more value.
Short form: In Twixtor you set input FPS param and you set the output frame rate in the AE Comp Settings and you render.
This sort of process has some issues at cut points as the last frame of a shot is typically too completely different then the first frame of the next shot. We provide a way to mark that, but for long format "frame rate conversion" it helps a lot if the movie is already broken down in layers per shot as what happens if you import a project from Premiere or from another editing system via Automatic Duck...
there is some sample projects in the Help/Support section of Twixtor:
http://www.revisionfx.com/products/twixtor/
see the jan 29 thread "Tidier workflow" below.
Pierre
