How do I play video's on my phone?

Do a search and find out what formats it supports, then convert your videos.

Can I convert them on RealPlayer?

Some more details would help.
1. What kind of phone do you have?
2. What format is the video in?
3. Is it a video you downloaded to your computer? Or is it on a webpage?

I’m going to guess that you have a Blackberry based on your username.
You can download a piece of freeware such as Blackberry Video Converter to make your videos compatible with the Blackberry, then transfer them over to your phone via File Transfer.

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