The primary purpose of user accounts on this site is currently all about offering more convenient access to the pastebin. It allows you to edit/delete your old pastebin entries even after your IP has changed which can be of importance to users with dynamic IPs. The login sessions depend on cookies so you will not be able to use this feature unless you enable them in your browser. If you do not have an account yet you may register one:

Register a new account

Specify your username and your password in the following writer and submit the data in order to log into your account.