Mixing sources in FCP

I thought that I read somewhere that you can mix different formats on the same FCP timeline without problems.
Is this true, and does it include different formats such as VHS, DV and HDV and/or different formats such as PAL and NTSC?
I know that you can convert PAL/NTSC in Compressor which is part of FCP Studio 2, but can you just use both together on a FCP timeline?
When its time to output, can you select which format to render to (PAL or NTSC)?
Thanks a lot for any advice.