Convert 60i NTSC video to 24p (with 3:2 pulldown so that it can be edited on a 29.97fps timeline), or 50i PAL to 25p by using a very high quality de-interlacer and proprietary algorithms.
De-interlace filters recreate the progressive look of film from interlaced video. Get all the effects in one master plugin--G FIlm Plus, or choose just the effects that you need as individual filters.
Digital Producer Magazine has a review of all the Natress filters (Film Effects, Standards Conversion, Big Box of Tricks), including example movies, by Heath McKnight.
Final Cut 7, X
After Effect 5+