Managing passwords is a difficult and sometimes stressful ordeal if you've got hundreds of different ones for various sites but Lastpass makes life that bit easier.
Lastpass is basically a free password manager that makes your web browsing easier and more secure by bringing everything under one password. Lastpass can create strong passwords that protect all sites, meaning that logging into your favorite browser, network or secure network becomes a one-step affair.
Lastpass is particularly useful for those that want to work together securely in different locations because it allows you share credentials to log in via Lastpass. This includes those that are working on Mac and Windows platforms as it works across both. Of course, the big concern is security - if your Lastpass password is lost or obtained by someone else, it makes everything protected under it vulnerable. However, it does use SSL and RSA encryption so you should be OK.
Lastpass is a great way to manage passwords under one umbrella without worrying about remembering the access credentials to them all.