Saving YouTube Videos:

I will suggest you to get FireFox Browser ( www.getfirefox.com ) to do it easy way, But here is one universal solution:

- Copy the URL of video from the address bar ( Place where you type www.sitename.com ) you want to store. ( something like this: http://www.youtube.com/watch?v=26_O-S4-JqI )

- Go to http://keepvid.com/

- Paste the url in provided area ( View Image Below )

- Hit DOWNLOAD

- Choose a Format ( View Image Below )

For Firefox Users:

- Install this Extension :
https://addons.mozilla.org/en-US/firefox/downloads/file/27979/video_downloadhelper-3.0.4-fx.xpi

- Read This Guide
http://www.downloadhelper.net/manual.php

Playing Youtube Videos:

Download any one of these:

- VLC Media Player
- Real Player

Convert Youtube Videos:

Download Orbit Downloader ( Cnet PopPick, 1,820,660 downloads )

or

YouTube Downloader ( 1,649,867 downloads )