and, just to add to the mix:
as of my search this morning, virgin schedules for Feb 2012 look decidely odd.
there is a daily (several times daily in fact) Virgin to Tobago. however, exercise caution. the only virgin flight that is direct is monday. all the others, including Thursday, are via NY, Bridgetown and Port of Spain. departures are from Heathrow and returns are to Gatwick. also, intriguingly, the Port of Spain-Bridgetown-NY legs are showing BWIA as the carrier
i assume that this is to do with the deal between Virgin, THA and the Ministry of Tourism involving the Magdalena and landing slots at Piarco. as it stands right now it all looks a bit strange. as i understand it, if the Magdalena doesnt open on schedule, Mr B has publicly stated that he will pull the extra flight (Monday) to tobago. this could suggest that the daily flights to piarco will be at risk if the deadline is missed.
also, miles plus money on the Monday flight is more costly than straightforward purchase.
oh, and the journey time on all but the monday flight is 25 hours from the UK - pax will need to overnight on Trinidad