I use the DownloadHelper add-on for Firefox to save the video to my desktop, then I copy the video to my phone, but it doesn't work for all videos. I tried UC Browser on one of the videos that DownloadHelper couldn't save and it didn't work so I guess it has the same limitations. Can anyone else save this and replay it without data? It doesn't playback for me with my cell service and wifi disabled.
http://www.youtube.com/watch?v=DgFif6AFVkc