How Strong Is Your Password?

Hackosis has a Brute Force Calculator which can tell you how long it would take a modern PC to crack your password. Some example results:

6 lower case letters 2 numbers 1 special character Your password is 9 characters long and has 988,530,483,200 combinations. It takes 3.60 hours or 0.15 days to crack your password on computer that tries 137,438,953,472 passwords per hour. This is based on a typical PC processor in 2008 and that the processor is under 10% load.

and

6 lower case letters 8 numbers 1 special character Your password is 15 characters long and has 988,530,483,200,000,000 combinations. It takes 3,596,252.95 hours or 149,843.87 days to crack your password on computer that tries 137,438,953,472 passwords per hour. This is based on a typical PC processor in 2008 and that the processor is under 10% load.