US Airways is offering a 50% bonus on points transferred in from hotel programs through March 31.
Miles have to actually post to your US Airways account with a transfer date by March 31, and the 50% bonus is supposed to take 6-8 weeks to post.
The obvious way to leverage this is with Starwood points, 20,000 points normally yield 25,000 miles but with this offer would yield 37,500 miles. 65,000 Starpoints would get you 120,000 miles — enough for a first class award from the US to North Asia (as far as Hong Kong. Or business class to Singapore, such as on the Newark – Singapore non-stop on Singapore Airlines.
Participating hotel programs are Best Western, Choice, Hilton, Starwood, Club Carlson, Hyatt, Marriott, Priority Club, Wyndham, and La Quinta.
Update: Ben notes that the terms and conditions of the offer say
Dividend Miles members will earn only one bonus when they transfer hotel points into Dividend Miles during the promotion.
I take it then you can earn a bonus on only one transfer, so make your transfer a good one (eg 60,000 Starpoints — you cannot transfer more than 79,999 in one go).