I knew that I was going to be close but no cigar for 1k several years ago. I was in grad school and the thought of losing my 1k was devastating. Too close to give up. So.
This was one of the times UA was running the $298 specials from JFK to LHR, and had corresponding cheap fares from the UK to the US.
At the time, I was living in upstate NY, flying regularly out of ROC. The 7 day fare to my home near SFO was ~$800 on UA. I calculated that the price of a back-to-back JFK-LHR-JFK and LHR-SFO-LHR (this was in the days before UA was beating agents to death with debit memos) was only $50 bucks more, well worth it for the nearly 18k miles. So, I drove to JFK, picked up the AM JFK-LHR, had a nice eve. in London, flew back LHR-SFO the next morning. At the end of the week, did the SFO-LHR, run, arrived the next morning, spent the day in London, took that evening's LHR-JFK and drove home that night.
That was nuts. I mentioned what I was doing to my seatmate on my first flight and it got around the entire cabin. I elected not to say anything on my other flights.
Greg99