I read this from a similar question on anther forum but not sure what it means .. Would this work?
Add full time hot outlet to 3 way switch circuit? - Yahoo! Answers
"I would replace the double-throw in the first box with a regular single throw for the light, fan, what have you. Using the red wire on that switch for your device, wire nut the remaining black to the supply black in the first box for the outlet you are installing in the second box. Now at the second box wire nut that red to supply your light to the black that feeds it from the old Common terminal of the old three-way switch and use the remaining black that was supplying one of the L terminals, now will be hot full time from the first box, to supply the terminals of the outlet going in the second box."