Heh heh heh . . . this is kinda funny, 'cuz I don't know what the <b>hell</b> I was thinking when I tried this, but it works (and my wife thanks me for it!).
I had plugged one of those 1/8" mini stereo Y-connecters with 1 input and 2 outputs (that you can buy at Radio Hack for a few bucks) into my front speaker output on my SB Live!. My speakers were always connected, but I would only plug in my headphones when needed. I guess I got lazy, or was otherwise whacked out of my gourd (like I am 50% of the time), but I moved the Y-connector to the other end of the speaker cord, so that the signal input was now going into the output of the Y (y'know, 2 sources to 1 device), then plugged the output into the speakers.
Here was the crazy part (or genius, as it were) . . . I plugged my heaphones into the other now "input" tail that was just hanging there. Amazingly enough (or maybe not), it worked.
I guess wire is wire is wire, and the signal will flow if it has someplace to go. I don't seem to have any loss (I am using Memorex Studio headphones, don't remember the model, and they have great sound with great bass in this config). I can plug them in when I want (since the connection is now just behind my right speaker instead of behind the case on the floor), and keep the power to my speakers turned off, and the only complaints I hear are re: the difficulty it is to get my attention.
Hope this helps!
VSP
<i> Thoughts are thinking; Thunk from knowing
<b> nwod </b> gniog em peek reverof sthguohT </i>