With any type of account, you can have unlimited Email forwarding, so you can have as many e-mail addresses as you want, but if you want to have another pop3 account (that is a mailbox where you store messages with us, rather than forwarding to another email address).
Please note that whilst you can have any email address you want (i.e.: firstname.lastname@example.org), pop3 accounts are first-come, first-serve. Popular ones like sales, info, david, john etc have already been taken, so choose something unique. Remember that people email you to your email address, not your pop account, so it does not really matter what you call your pop3 accounts, these are simply little mailboxes (or pigeonholes) where the mail sent to you is kept until you retrieve it.