Too many passwords? Try a password manager

How many different online accounts do you have?  Online banking, e-mail, social websites, etc.  Add on to that all of the online shopping sites, and you're probably over 20 at least.   How do you remember the passwords?  Some people use a single password for every site.  That's NOT a good idea.  Take a look at the linkedin security breach a few weeks back and you can see why.  If you used the same password for LinkedIn that you did for your e-mail, the data thieves now have access to your e-mail, which will pretty much give them access to nearly every account you have.
So what is the solution?  You should have a different, hard to guess password for each site.  To keep track of these passwords, you should use a password manager.
There are 2 password managers that I have used and recommend:

Keypass is an Open Source application that uses a local database file to store your passwords.  The file is secured with a password and optionally a key file.  I would advise setting the password for the key file to be a long phrase that you will remember (i.e. Mydogspothasfleas).  Vary the capitalization and change letters to special characters like changing all of the "s" to $.  There is a portable version available that can run from a USB stick or portable hard drive.  There are also versions available for iOS (iPhone, iPad, and iPod Touch).  I like to use iKeePass. 
Once you have created your database, you will be prompted for the password to save it with. DO NOT FORGET THIS PASSPHRASE.  There is no way to retrieve it if it lost.  In order to access the database from your portable device, you should save it to a publicly accessible location on dropbox.  You don't have to worry about the security of the file you used a long passphrase, right?
You can add sites under different categories and add categories as needed.  It's a simple and easy way to securely store your passwords.  You can copy the password from KeyPass into the clipboard so you can paste it into your browser.  When using the PC version, you can even log into the website directly from Keypass.

Lastpass takes a different approach than Keypass.  Lastpass will store all of your passwords on their server.  Don't worry, they don't have copies of your passwords, they are all encrypted before being sent to their server.  So, as they warn during the creation of your account.  DO NOT LOSE OR FORGET YOUR PASSPHRASE.  There is no way for them to retrieve it.  If it's lost and it needs to be reset, all of your data will be lost.
Lastpass functions as an extension to your web browser and will automatically fill in your username and password when you log onto the site.  Instead of having to enter all of your sites into lastpass, you will be prompted to add a new entry when Lastpass sees a new site it does not recognize.
As with Keypass, Lastpass is free to use.  However, there is a $12/year option that adds many features including access via a mobile application,  "IE anywhere" which allows you to use Lastpass with Internet Explorer without needng a plug-in, no advertisements, and priority support.

If you are just looking for simple password management, I would recommend Keypass.  Lastpass takes a little more to setup, but once it is setup on a computer, Lastpass is nearly invisible to the user.