For those of you doing mileage runs to SIN (and SEL, HKG, or TPE), UA is offering 2000 extra miles for r/ts in coach (5000 miles in C and 7500 in F) if you route yourself through SFO (or LAX) and complete your trip by January 31, 2001. You need to pre-register for it with promotion code MPA 800. This promo has been on the site for a month now but I didn't find out until after I flew back from SIN. Fortunately, I called up MP and got credited an adjustment without any hassles. Details from the site about this promo are below...

Through January 31, 2001
Earn up to 7,500 bonus miles on selected routes to Europe and Asia
Earn 7,500 Mileage Plus bonus miles in First Class, 5,000 bonus miles in Business Class or 2,000 bonus miles in Economy Class when you purchase and fly a roundtrip on any one of the following routes:

United:
Los Angeles-Singapore or Tokyo
San Francisco-Hong Kong, Seoul, Singapore or Taipei
Washington, D.C.-Frankfurt or Amsterdamc
Singapore Airlines:
Los Angeles-Tokyo, Taipei or Singapore
Newark-Amsterdam or Singapore
New York-Frankfurt or Singapore
San Francisco- Hong Kong, Seoul or Singapore
Travel must be completed between November 1, 2000, and January 31, 2001. This offer is not combinable with any other offers. Offer valid only on flights departing and arriving Monday through Thursday. Blackout dates apply December 18-21, 2000, and January 22-24, 2000. Offer valid only on flights operated by United and Singapore Airlines. Not applicable to code share flights operated by other airlines. Offer subject to change without notice; other restrictions may apply. You must register for this offer before departure. You only need to register once. Click here to register online or call 1-800-447-6772 and enter offer code 631.

Click here to book online at united.com. Or book your trip with United International Reservations at 1-800-538-2929. (MPA 800)