What is best Mac/PC Compression software or format?

[HowardNeedsHelp]

Hi,
I am a Mac only computer person and I want to email or make available for download some large movie files. What is the best compression software that runs on Mac and can be opened by PPC Mac, Intel Mac, and Windows PC?

I am open to spiting the files into segments, but have never done that before and am not sure at what GB size one should split a file and one the other end the person is supposed to get them back together. What is the largest files size that should be compressed to send by email? Which compression software will give me the best result for my money? What is the best cross platform format .zip vs.rar?

Thanks!

[Baldrick]

.mp4 with h264 video. Convert with for example handbrake.

Or upload to vimeo, youtube, etc.

[rumplestiltskin]

Once you transcode to H264 (and Baldrick is spot-on with Handbrake), "zipping" doesn't do anything except probably make the size larger. This is because H264 videos are already highly (and efficiently) compressed. Don't split them (unless the file transfer service you are using requires smaller files). Sendspace.com permits 300MB files and is free. However, it sounds as if you are considering files of multiple gigabytes (even after H264 compression); if so, then use something like Archivator to "rar" the file (without compressing if possible as that doesn't provide any benefit with H264 files) and accomplish the splitting at the same time. Re-joining the segments and un-rar'ing can be done on multiple platforms with various free apps.

Let us know how it goes.