US Airways is offering free silver status for 90 days.

• Registration required by August 15.
  
• Must purchase a non-refundable ticket at usairways.com for travel only on US Airways/US Airways Express and only for travel in the United States.
  
• Ticket purchase required by August 15 for travel beginning by September 15.
  
• Status will take up to 7 days to be reflected in your account after purchasing a ticket.
  
• Members who were elite members in 2009 or who have had complimentary or trial US Airways elite status within the past two years aren’t eligible.

US Airways Silver status is of course also Star Alliance Silver, which gets you a free checked baggage allowance.

(Via One Mile at a Time)