Many folks are increasingly worried about their United Mileage Plus miles, as the airline publicly discusses the possibility of liquidation and as the effects of an invasion in Iraq play havoc with United’s revenue.

Randy Petersen, whom I much respect, thinks that United miles are certainly safe over the coming weeks, and I’ve gotten the impression from him that he believes the Mileage Plus program will be safe (in some form) even if the airline itself goes away. His argument (though I don’t wish to speak for him, and it’s possible that I won’t do it justice) is that the loyalty program is a value creator rather than a cost. Air Canada sold off a chunk of it’s program for a nice amount of money. Randy thinks Mileage Plus is worth perhaps $3 billion, whereas UAL, which is in chapter 11, is only valued by the market at about $50 million.

Nevertheless, many people are burning their miles or looking for escape hatches. One hatch has been to transfer miles into Hilton points. One mile = two points with Hilton.

Unfortunately, though the Hilton website isn’t yet clear on this, the option has apparently been closed down. I don’t know the story yet, but it could either be that Hilton didn’t want to give out points on the chance that it would never collect its money from United. Another possibility is that United simply didn’t want to be buying Hilton points any longer, when it needs to conserve cash. Either way, the Hilton option appears to have gone away.

The only remaining option for moving miles out of your Mileage Plus account that I’m aware of (other than redeeming awards, that is) is to launder them through the Diners Club credit card.

I’m not an expert on this, as I don’t personally hold the card, but about 5 or 10 minutes reading up on Flyertalk has revealed quite a bit. Here’s what I learned (although I make no warranties that I’ve learned everything correctly!).

You can transfer United miles into Diners by calling 1-800-447-6772. You will enter your Mileage Plus number and Zip Code, and then enter offer code 015. It will then ask you to reenter your Mileage number and Club Rewards number.

UA miles transfer 1:1 into Diners points. 2 Diners points transfer into 1 airline mile. So you’ll suffer a 50% devaluation, unless you wait for summer and the expected double points promotion with British Airways (in which case you’ll essentially transfer 1:1 into BA).

However, there have been lots of changes to the British Airways program that make this less than ideal — including point requirements for premium awards that have recently risen as much as 300%. And there’s no guarantee that the double points deal will be repeated, although it has been an annual affair of late.

And if you do want to take advantage of a British Airways double mileage transfer, make sure that you have a British Airways Executive Club account before July 1, when new restrictions kick in.

It’s been reported that transfers into Diners points can happen quickly with some airlines (CO) and take quite some time (due to once-monthly sweeps) with United. It’s also been reported that the names on the accounts (frequent flyer account and Diners) have to be the same with some airlines (American, British) but not on other airlines (all others?). I have no direct experience with either of these things.

Diners does impose a fee for converting its points into miles — $0.95 for every 2000 points converted.

There is a limit of 50,000 miles which you can transfer at one time. It seems that that transaction needs to complete before requesting the next one. There’s a rule which says that 50,000 miles is the most you can transfer out of United into Diners per calendar year. Many folks report that they’ve exceeded this limit.

Do you have any experience transferring miles into Diners? If so, leave a comment with any experience or tip you’d like to share. I’d sure like to get better educated about this.