A report on AnandTech shows a brief video of the tech running Unreal Tournament on an Apple mobile (embedded below), and says Epic is preparing to name a number of other mobile platforms the tech will work with at CES in January.
The demo's modified version of UT uses a virtual on-screen joystick and tilt controls.
Of course, UE3 is a famously powerful engine - and requires sufficient hardware support to boot, so the engine only works on iPhone 3GS given its support for OpenGL ES 2.0, which standard 2G and 3G plus older iPod Touches don't feature.
The AndandTech report says that Epic isn't offering licences for the mobile version - yet. Instead the firm is demoing its new innovations to show how it is forging ahead with new platforms, ideas and technology.
But the iPhone version will eventually see the light of day - so in theory UE users can start toying with ideas now and in future port them over to the mobile version.
The report suggests, however that the mobile version won't be available to those entry-level Unreal users that access the UDK, it will only be available to fully paid-up licensees.