I wuld like to watch my existing DVDs on my Iphone. Can anyone suggest how to do this? Is there software that can help?
Sure! Download Videora or QuickMedia to convert your DVDs to iPhone videos. Then you can use iTunes to put them on your iPhone. But personally I recommend using a free iTunes alternative such as the ones listed below: http://ipodmanagers.blogspot.com/
I use Handbrake - it is really simple to use and has an iPhone/ iPod Touch button that formats it perfectly for both.
Handbrake is just perfect for that job! It's fast and always gets your DVD's (with subtitles!) to your iTouch/Phone.