Windows Movie Maker includes the ability to add subtitles to home video. From the tools menu, choose Titles and Credits, click on the option to Add title on the selected clip, add your text and then configure text size and positioning.The only trick is that this gets complicated if you need lots of text. And the subtitles will be a permanent part of the finished video as there is no way to toggle them on and off.Here's a visual tutorial for both Windows Movie Maker and iMovie:
http://www.jakeludington.com/ask_jak...subtitles.html