We usually wait until a homebrew project has had time to mature past its alpha builds before calling the game to your attention, but we take exception with any and all plans for a portable X-Com: UFO Defense. Our love affair with the turn-based, tactical title has been a romance with few equals, inviting comparisons with Shakespeare's tragic coupling of Romeo and Juliet. Should society ever try to separate us, you'll find that we've already taken measures to leave this miserable world, our lifeless arms entwined with X-Com's diskettes even in death.
Blue_knight has posted screenshots of the progress he's made so far with adapting the game's data for the DS. The handheld clone already features tileset loading/creation, four height views, and touchscreen support for scrolling around the battlescape. Though there's still a lot left to implement, like fog of war and a map overview on the second screen, that hasn't stopped us from scouting countries for potential bases and trading tips on how to best attack Chryssalid terror sites.