This article in Lifehacker - “How I’d Hack Your Weak Passwords” outlines how simple passwords are easily hacked (5 minutes for a lower case 6 character password, assuming it’s not in the dictionary in which case it would be faster), and how easy it is to make your password more secure.
Here are the first 3 password tips, read the article for the full list:
Randomly substitute numbers for letters that look similar. The letter ‘o’ becomes the number ‘0′, or even better an ‘@’ or ‘*’
Randomly throw in capital letters
Think of something you were attached to when you were younger, but DON’T CHOOSE A PERSON’S NAME! Every name plus every word in the dictionary will fail under a simple brute force attack