London Heathrow to Euston Train Station

Fastest would be the Heathrow Express to Paddington and a taxi from there to Euston. Very expensive. The Heathrow Express fare is £19.00 if bought at the station and £18.00 if bought online. Only about 15 minutes slower would be taking the Tube all the way: Piccadilly Line to Green Park and the Victoria Line from there to Euston. The ride will take just under one hour. The cash fare for a single ticket is £5.30.

Quicker still would be helicopter to Tower 42 (is that what they are calling the Natwest Tower these days?) and then motorcycle. Not available to the public though.

If it was the middle of the night, probably a motorcycle courier who meets you at the arrivals hall would be the fastest possible way for a commercial transfer.

Thanks for the replies. We chose the Heathrow Express/taxi option, but I liked the helicopter and motorcycle ideas for the fun factor.