AS flies LAS / LAX / PHX / SFO to Anchorage as well as various East Coast destinations, all of which would be over 2000 miles and hence net 140 TPs per segment. Add in a little bit of creative routing and you could get your 600 points in one trip. Well, almost

However as Confus says you still need get the four qualifying flights and, no, BA doesn't waive the requirement for those of us who live abroad. I tend to get my four flights around Christmas as I usually head back to the UK around then, and my membership year starts / ends in December.

I'd definitely agree that it can be quicker and cheaper to do shorter 40 TP flights. I have three consecutive weekends in September where we'd planned to do LAS - LAX - LAS which would be 80 TPs for $238 but due to a schedule change we're now doing LAS - SFO - LAX - LAS so it's 120 TPs for $238.