coOpera

Opera browser features a brilliant messaging client that includes e-mail client (POP3/IMAP), news reader (NNTP) and feed reader (RSS/Atom). The messaging client provides a convenient way of keeping track of information about people you communicate with.
However, if you are using Opera e-mail client, or just made an attempt to switch to it, you may have noticed that Opera has no particular support for importing contacts from other e-mail software. For example, migrating contacts from Microsoft Outlook and Microsoft Outlook Express is not easy.
In order to import your contacts to Opera, you may need to use a tool that will save you a lot of time retyping the names and addresses from one address book into another one.
coOpera is such a tool. It helps to convert your Microsoft Outlook, Microsoft Outlook Express, Gmail and Yahoo! Mail contacts to Opera format. All you need to do is export your contacts to a CSV file, choose the contacts you would like to convert, and finally, import converted contacts to Opera browser. Everything else will be done automatically for you!
coOpera migrates all information that an Opera contact can store: contact name, e-mail addresses, postal addresses, phone and fax numbers, notes and website address.

coOpera is absolutely free for personal, non-commercial use.