Since you mentioned United, there's the First USA United MP card. Of course, this is offered by what is widely regarded as the WORST credit card bank in the USA. On top of their best-in-class BAD service, they charge you a 3%(!) foreign purchase surcharge....again a bad mark they try to HIDE in the FX conversion on the bill.......yet, if you still want to get this card, apply over the phone for the promo that offers a free domestic companion tix (that promo can be found thru the "search" function of this website)

If you want a good VISA/MC, Northwest/US BANK is running a 10,000 promo for signing up. Plus you can tack on 3,000 extra miles for signing up for Auto bill pay. Total= 13,000 for $55. If you go to the Northwest thread of this website, you can even score 10,000 extra miles for playing their promo of completing 5 transactions with partners by end of April.....so that's 23,000 miles!