Two months ago, I transferred a few points to my wife's UA account to bring her up to 25K. So that one works...at least for same last name. I know AA definitely does not because I tried it as well.

I frequently use DC points for top-off purposes. To me, this beats even the BA deal because I can top-off right when I want an award. Helps me get value out of the 3 or 4 accounts I have with airlines I fly only a couple times a year. I also funnel iDine miles to those more-dormant accounts for the same purpose.

Although I haven't done it: if you want to get cash for your DC points, you can swap 25K for 1 Southwest ticket. Once you have a Southwest ticket, you can freely sell it on the open market (unlike other FF tickets) - I think they fetch around $300 these days.

Other than that, you can't beat the BA promo...

We're new to DC, am I reading this correctly? I went to the DC site & it looks like you can transfer AA miles to points & then you can transfer those points to double miles on BA? We'll already have 12,000 DC miles...

Where is the documentation for double miles on BA?

Thanks!

If you want airmiles, then all the stuff mentioned above is good. I use my Diner's points quite often to transfer into hotel points since I'm miles heavy & hotel points short. Also, one year I redeemed points for 8 Waterford red wine balloon glasses, which was great. If you're ever miles & hotel points heavy, then merchandise can be a good use of points too.

Although WN might be a generous airline, they're not this generous--in the very first rule in the Notice of Incorporated Terms on the back of the Rapid Rewards ticket it states that the "Award Ticket flight coupon is transferable (but is void if sold)." So, although there may very well be a practice of selling WN RR tickets, Southwest does officially prohibit this.

That's correct, but you lose half the AA miles' value in the process. 10,000 AA miles convert to 10,000 DC points, but a DC point is essentially half an airline mile. So, with the double BA promo (assuming they run it this summer; precedent says they will, but lots of things in the travel biz aren't quite the same now as they were) you end up where you started. It's a good loss-free way to get miles from AA (or UA) to BA, if you want to do that, but you don't come out ahead.

You definitely don't come out ahead. If Diners Club does the BA promotion again this summer, you will get the same number of BA miles as you had AA or UA miles. However, with BA's new program dilution, premium awards on BA cost much more in terms of miles than before. See the BA board for details.