T-Mobile has just released the free Windows Mobile 6.0 OS upgrade for Windows Mobile 5.0 based T-Mobile Dash Smartphones. The upgrade is available for Windows Mobile 5.0 ROM version 1.22.531.4 or later.

To check your ROM version, goto Start–>Settings–>More–>System Information
The upgrade contains Windows Live services, Voice Command 1.6 and Pocket Office (Word, Excel) to create and edit documents on the go.

Visit the T-Mobile Windows Mobile upgrade website here for more details.

To download the free OS upgrade, click here