I ran across this plugin today, seems simple enough... it resumes playback of video or audio files from the last location that it was playing from... I'm not positive how it all works, I have just a tad bit of use so far, but basically when you close the player and then launch the file that it was playing when it closed it just jumps right to where you left off...

http://www.wmplugins.com/ItemDetail.aspx?ItemID=483

I thought maybe this would come in handy...