As an eligible iPhone users, add DVD movies to iPhone and save youtube to iPhone is the basic skill. Now, it's said, iPhone 3G will launch on July 11th, new features about the new iPhone 3G here - http://www.daniusoft.com/tutorial/iphone2.0.html, it's really a good news to iPhone fans you and me.
Following are three ways to save Youtube to iPhone I often used:

Part one. Convert Youtube to iPhone (video to iPhone 3G) with iPhone Video Converter (for Windows users).

1.Copy and paste the link of video from Youtube in this website: www.videodownloadx.com.

Then click download and right click on 'the download then save as.', while saving, you can type the video as "title.flv".

2.iPhone can play MP4 video, MP3, m4a audio.
After downloading, you should convert the *.flv to *.mp4 format. So you can download third party software to convert Youtube to iPhone (video to iPhone 3G). If you already know how to convert Youtube to iPhone (video to iPhone 3G), you can go to Part two; else, as convert Youtube to iPhone I prefer using Daniusoft Video to iPhone Converter, it converts video formats to iPhone including AVI, MP4, MPEG, WMV, XviD, H.264, DAT, MOV, ASF and FLV, etc. to iPhone MPEG-4, H.264, and rip video audio to iPhone MP3, M4A, AAC. It can also convert Youtube video to iPhone 3G, too. You can free download Daniusoft Video to iPhone Converter - http://www.daniusoft.com/video-to-iphone.html here and convert Youtube to iPhone with its guide.


Part Two. Convert Youtube to iPhone (video to iPhone 3G) with iPhone Video Converter (for Mac users)
1. Step 1 and step two as above.
2. After save Youtube to iPhone, Mac users can use iSquint. iSquint is an iPod video conversion app for Mac OS X that can be use to convert Youtube to iPhone too. It's a free application with similar export features as Daniusoft Video to iPhone Converter. iSquint is awesome! It can be downloaded at http://www.macupdate.com/info.php/id/19769/isquint.


Addition: You can burn the downloaded Youtube video to DVD with DVD Burn software.

Part Three. Save Youtube to iPhone (video to iPhone 3G) with MxTube.
MxTube is a YouTube video downloader that allows you to save YouTube videos directly to your iPhone. You can download it here - Installer app http://www.installerapps.com/2008/03/13/mxtube/.

When you open the app you will see a lower menu bar with four options; Featured, Search, Videos and Downloads. The Search option allows you to search YouTube for videos. YouTube actually has two versions of every video, high and low quality, once you have found a video you would like to download, you can select either high, low, or both. The videos will download in sequence and in the background. Once it's done downloading, the video is available from within the application.


The Youtube video to iPhone can help you more: http://youtube.com/watch?v=m-6BceaGT6A.

Conclusion: The first and second way to convert Youtube to iPhone(video to iPhone 3G) needs the third party software to convert video to iPhone, if you don't care to download the convert software, then the first and second way is the best way for you to convert Youtube to iPhone, Because it has better video quality for iPhone.
The third way to save Youtube to iPhone(video to iPhone 3G) needs Mxtube, it's free but you won't be able to sync the videos back to your computer. If you don't care to store video back to your computer, then it's also a good way for you.