As noted above, the BA lounge is probably your best bet unless you have access (or want to pay to access) to the centurion lounge. Although small, it is still quite nice.
See:
http://www.flyertalk.com/forum/briti...e-options.html
http://www.flyertalk.com/forum/briti...o-lounges.html
http://www.flyertalk.com/forum/briti...fo-lounge.html