I created this little bookmarklet a few days ago to instantly create a random 10 character password. It's pretty handy as I'm always needing to create a new secure password.
If you need it more secure, you can edit the character list in the str variable, and edit the length of the password via the for loop. In this version, I've stripped out characters that look alike as it's annoying when can't tell exactly what the character is.
To use it, simply drag the link below onto your browser toolbar, and then click it when you want to create a random password.