I made my first and only text adventure game in QBasic through MS-DOS (Yeah, it was the early 90s). The game was called Trapped and took place in a prison cell. Your job was to get out of the cell by moving bricks, looking in the mirror and talking to cellmates. It took me about two days to make the game and 30 seconds to play it. 

I found a fun flash text adventure game through Big Spaceship: Think. Play it here.

I think the IPhone would be a great platform for text adventure games. Maybe I´ll make Trapped II some day. Maybe not.