The handset, which runs on the new Linux-based Maemo 5 software, will be available from the phone retailers' website from Boxing Day (December 26).
The Nokia N900 will be exclusively available on Vodafone, and can be purchased from the network direct.
Web users can register their interest in the handset by visiting Vodafone's dedicated webpage.
While Vodafone did not release pricing, the Carphone Warehouse said the handset would be free of charge on a £35 per month contract featuring 900 minutes of calls.
The Nokia N900 features a 3.5in 800x480 display, along with a slide-out qwerty keyboard, 1GB of memory and the ARM Cortex-A8 processor.
Users will also benefit from a 5Mp camera with Carl Zeiss lens and dual-LED flash.
See all mobile phone reviews