The Facebook Chat For Windows Mobile: Fim v2.12 + WM6.5

Features: Facebook Chat, Status Feed, Notifications & Inbox Indicators
Picture & Video Uploads Directly From Your Phone, Integrated m.facebook.com Browser

Advantages: Lightweight, Finger Friendly, All Display Resolutions, Free Full Version
No 3rd Party Registration or Data Access, AppToDate Support

Supported Platforms: Windows Mobile - WM6.5, WM6.1, WM6, WM5, 2003SE, Windows Phone 7


Windows Mobile 5.0, 6.0, 6.1, 6.1.4, 6.5 (v2.12) Download (cab, 130 KB)

Windows Phone 7 (v2.20) Download (Marketplace)

Installation:

Download the mobile installer (.cab file) to your desktop. Sync with your mobile phone and copy the .cab installer to your phone. From your phone go to Programs -> File Explorer, navigate to the .cab file and select it. The Installer should do the rest.
or navigate to http://get.mosko.mobi on your Windows Phone, choose open, the installer should do the rest.

Optional: WM6.5 CHome ("Titanium") Plugin

FAQ/Notes/Troubleshooting:

"Connection Failed": usually due to email or password typed incorrectly. if you are positively sure you entered everything correctly then if you have special characters in your email or password replace them. only numbers, English letters and of course @ at the email allowed, also keep in mind that facebook passwords are case sensitive.

WM BUILDS 6.5.3 / 6.5.5 blank web pages: to fix the internal browser problem use the cab from this post

touch/x/iphone/lite.facebook.com: doesn't open the way you expect in the integrated browser, which is the same as explorer in wm6.1, so there is not point integrating it.

WAP: fb chat needs solid 3g/wifi/gprs internet connection. even if your operator allows some facebook features thru its wap proxy, not sure it will be enough to use chat feature of facebook

3G: some 3g issues were fixed since version 2.2.8, If you still can't connect over 3G, check the settings on: Start->Settings->Connections Tab->Connections->Advanced->Select Networks->Programs that automatically connect to the Internet should connect using.. You should choose your operator's internet connection and not its wap portal.

WM 2003 SE: Setup CAB will not work, unpack it and use standalone executable (fim.exe)

Smart Phones (Windows Mobile Standard with no touch screen): supported since version 2.2.7, if you have problems/comments/suggestions post them in this forum

Photo/Video Uploads: If you are having problems with photo or video uploading, update your .NETCF to 3.5

Credits goes to: XDA-Developers (for more information and guidance follow this link)