In reply to The Lemming:
The mains electricity supply in the U.S. is 30 cycles per second, the supply in the U.K. (and Europe) is 25 cycles per second, this is why NTSC, the U.S. T.V. standard, was set at 29.97 interlaced frames per second (59.94 fields per second) and PAL, the U.K. standard, was set at 25 frames per second (50 fields per second). The PAL system had more scan lines however so whilst NTSC may appear a little smoother, PAL should be a little more detailed. In the days of analogue T.V.s using cathode ray tubes you couldn't readily display an NTSC video signal on a PAL T.V. and vise versa.
Nowadays the high definition formats have the same number of pixels whether they are displayed at 25, 30, 50, 60 frames per second or whatever, and flat T.V.s and projectors are designed to cope with multiple standards, so unless you plan to display your footage on an old C.R.T. display it shouldn't matter what frame rate you choose. There are however a couple of considerations: If you plan to create a DVD then it is probably best to stick to PAL (25 fps, 720x576) DVD players are often set up to play PAL disks at their native settings but convert NTSC disks to PAL, with a resulting loss in quality. If you plan to display the footage on a computer then display settings often default to 60fps so some multiple of 30fps would seem to be the best bet. One further consideration is that if you are filming using artificial light, particularly fluorescent lighting, then it is best to match the frame rate to the frequency of the electricity supply to minimise flickering.