Well, the fun just got extended for a couple more weeks. The cheap ($1,500ish total roundtrip) Delta fare sale from Boston, Miami, Tampa, Orlando, and Jacksonville to London has been extended to March 31. Ticket by March 31, 2011 and fly between March 26 - August 31, 2011. Remember, these fares book into I class, so you get a 50% SkyMiles and MQM bonus. So for a Tampa- Atlanta- Boston- London flight, you get 13,851 SkyMiles and Medallion Qualifying Miles for each roundtrip (plus any Medallion bonus you might have). The transatlantic flights are in Delta’s lie-flat BusinessElite cabin, so you will be experiencing one of the better business class products out there.And if you don’t live in one of the target cities, you can always buy a separate ticket - for example JFK-BOS roundtrip can be as low as $100 round trip - just make sure you give yourself ample connection time, because Delta won’t automatically protect you if you miss your flight due to booking two separate itineraries (though since it’s all Delta, they’d probably take care of you).To search for these fares, I recommend doing a flexible date search on Delta.com -> Planning and tools -> Book a flightThen enter either BOS/MIA/JAX/MCO/TPA to LHR and select “My Dates are Flexible” and then under cabin “First/Business” and then either select a range of dates +/- 3 days or weekend travel (which will show a grid of Thursday-Tuesday travel).Some screenshots:Key things to note per the fare rules: (Seems to indicate a Saturday night stay, but others have booked without it)MINIMUM STAYSign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.TRAVEL FROM INBOUND TRANSATLANTIC SECTOR MUST COMMENCE NOEARLIER THAN THE FIRST SUN AFTER DEPARTURE OF THE OUTBOUNDTRANSATLANTIC SECTOROR - TRAVEL FROM INBOUND TRANSATLANTIC SECTOR MUSTCOMMENCE NO EARLIER THAN 3 DAYS AFTER DEPARTURE OFTHE OUTBOUND TRANSATLANTIC SECTOR.MAXIMUM STAYTRAVEL FROM LAST SEGMENT MUST COMMENCE NO LATER THAN 90DAYS AFTER DEPARTURE FROM FARE ORIGIN.NO STOPOVERS PERMITTEDTHE FARE COMPONENT MUST INCLUDE TRAVEL VIA EACHTRANSATLANTIC SECTOR ONONE OR MORE OF THE FOLLOWINGDL FLIGHT 270DL FLIGHT 271DL FLIGHT 144DL FLIGHT 145DL FLIGHT 260DL FLIGHT 261ANY TIMETICKET IS NON-REFUNDABLE IN CASE OF CANCEL/NO-SHOW.WAIVED FOR ILLNESS OR DEATH OF PASSENGER OR FAMILYMEMBER.NOTE -1. RESERVATION CANCELLED PRIOR TO THE ORIGINALLYSCHEDULED FLIGHT RETAINS TICKET VALUE/LESSAPPLICABLE CANCELLATION FEE IN CHANGE PARAGRAPHUP TO ONE YEAR FROM THE ORIGINAL DATE OF TICKETISSUE. IF THE TICKETED FLT RESERVATION IS NOTCANCELLED PRIOR TO TICKETED FLT DEPARTURE TIME/REBOOKING IS NOT PERMITTED AND TKT HAS NO VALUECHANGESANY TIMECHARGE USD 400.00.CHILD/INFANT DISCOUNTS APPLY.NOTE – MAY ONLY CHANGE DATE OF TRAVEL/NO REROUTINGPERMITTED- ALL TICKETS MUST BE REISSUED- SEE /CHILD/INFANT DISCOUNT/ IN FARE RULE TODETERMINE IF APPLICABLE - NO CHANGE FEE IF UNDER2 YEARS OF AGE NOT OCCUPYING A SEAT- RESERVATION CHANGES MADE PRIOR TO THE ORIGINALLYSCHEDULED FLIGHT RETAINS TKT VALUE LESS THEAPPLICABLE CHANGE FEE UP TO ONE YEAR FROM THEORIGINAL DATE OF TICKET ISSUANCE.- CHANGES RESULTING IN A HIGHER FARE MUST BE ADDCOLLECTED AT THE TIME OF REISSUE[card card-name=‘Starwood Preferred Guest® Credit Card from American Express’ card-id=‘22034416’ type=‘javascript’ bullet-id=‘1’]