thanks for the info... that's the plan I was thinking about and looks to be the best route for me. My only problem is trying to get the best value ticket for the train ride.

If I arrive at LHR at 13:40 than have to go thru customs and get my bag how much time should I allow between the arrival and catching the bus?

I've tried contacting southwest trains customer service about purchasing a ticket thru heathrow online?? still waiting for reply..

thanks again.. tim