I'll put my hand up to being a flask user. I make an extra coffee in the morning to have on the train to work as I recover from cycling to the station... we refer to this as a "flask white".
On the return stretch, I usually carry tea. However, I note that Starbucks are kindly offering to fill my flask on the house tomorrow (15 April).
Details here:
http://www.moneysavingexpert.com/deals/ ... #starbucks
Maybe this is of interest to others in the flask/insulated cup community
Phil
P.S. Happy to detour via any coffee shop in Soho should there be a better offer...