Does anyone know the name of the train station in Moreton-In-Marsh? I need to take the train from the station in town to Heathrow to catch a 10:30am flight on 06/18/10. I believe the trains run every 1-2 hours but I do not know what the names of the train stations are to book the pass on National Rail.
The station is called Moreton-In-Marsh: I don't know why you weren't able to find that on the website. The three-letter code is MIM.
Looking at the current times for Mon-Fri (may change by mid-June but should be comparable), the first train is at 0548 and gets to Paddington at 0729. The later ones are 0616-0759, 0706-0851, and 0727-0929. Once you get to Paddington you should be able to get to Heathrow by Heathrow Express (15 minutes, expensive) or Heathrow Connect (25 minutes, a bit cheaper). I don't know what your check-in time is, but I'd go for the 0706 at the absolute latest and preferably one of the earlier ones.
Are you flying home from Heathrow rather than to somewhere else in Europe? If so, it's wise to be at the airport three hours before your flight is scheduled to depart. (That's not possible, even taking the first train.) Assuming those are your plans, it might be wise to spend your last night in London. If you decide to take your chances, then you had better take the first train which departs at 05:48 and arrives at Paddington at 07:29. Buy your ticket at the station. The fare for trains departing before 09:30 on weekdays is 28.50 GBP.
The Heathrow Connect runs every 30 minutes, departing at 3 minutes and 33 minutes past the hour. The first train you could catch leaves at 08:03 and arrives at Terminals 1-2-3 at 08:29 (only two hours before your plane leaves). The fare is 7.90 GBP.
The Heathrow Express leaves Paddington at 10, 25, 40, and 55 minutes past the hour and the ride to Heathrow takes 15 minutes. So if you catch the HEX leaving at 07:40, you'll arrive at Heathrow at 07:55 (2 1/2 hours before your plane leaves). If you book your ticket online, the fare is 16.50 GBP. If you buy your ticket at Paddington, the fare is 18.00 GBP. If you buy it after you board the train, the fare is 23.00 GBP.