If you are looking for complete Facebook client with advance functionality with sleek UI then you must have fMobi, although there are many Facebook clients available for Nokia phones but fMobi offers latest interface with multiple user options.
fMobi is a Qt based apps available for Symbian^1, Symbian^3 and Maemo. You need to install qt first, before installing this app.



Features:

* News feed
* Chat
* Profile
* Liked Pages
* User info
* Groups
* Events
* Commenting / Liking
* View comments / likes
* Albums / Photos
* Notifications
* Landscape / Portrait

Supported Devices:  Symbian S60V5: Nokia C5-03 , Nokia C6 , Nokia X6 , Nokia X7, Nokia 5800 Xpress music , Nokia 5230 , Nokia 5233 , Nokia N97 , Nokia 5530 Xpress music , Nokia 5250 , Nokia N97 Mini , Sony Ericsson Vivaz Pro , Nokia 5235 , Nokia 5800 Navigation edition , Sony Ericsson Satio , Sony Ericsson Vivaz , Samsung I8910 Omnia HD, Symbian Belle and other Symbian S60V5 devices.

Symbian^3 :  Nokia N8 , Nokia E7 , Nokia C7 , Nokia X7, Nokia C6-01, Nokia 700 and other Symbian^3 devices.

First download qt from here: Qt 4.7.3, QtWebKit 4.7.3 and QtMobility 1.1.3 , install it and then download and install fMobi client from below:

Download for Symbian^1 (v1.4), Download without smart installer for Symbian^1 official : here: Download for Symbian^3 / Anna / Belle (v1.4),Download for Maemo (v1.4) Please bookmark (ctrl+ D) my for future updates.