1) Here is a YouTube URL http://www.youtube.com/watch?v=-y-s6CQoOIQ
2) Edit the URL - or any youtube URL by adding the word 'kick' prior to youtube http://www.kickyoutube.com/watch?v=-y-s6CQoOIQ
3) This will then take you to a new site that allows you to download videos in multiple formats such as MP4, FLV, HD, MP3 and more.
4) Highlight your chosen format and hit the GO button and your download will begin.
You can also see a download history and other recommendations.
Try using www.FastStone.org. It takes about half the time for each capture and has more features. It is Freeware.
Screen dumps using Macs
apple + shift + 3 = gives whole screen
apple + shift + 4 = allows you to highlight part of the screen which will then be captured, file saved onto desktop as picture1, picture 2 etc.