Currently there are only two avenues to get MQMs without flying. You can get a Delta-branded Amex card that offer's a signing bonus of x-number of MQMs. However with this being mid-November I can't promise you will see those MQMs before Dec 31. If you already have a Delta-branded Amex you can spend a certain amount prior to Dec 31 (calendar year spending) and receive an MQM bonus. For the Platinum Delta Amex card on must spend $25K within a calendar year. The bonus is 10K MQMs, which would be overkill for your needs but the leftover will roll over into 2010.

You need to find a cheap flight somewhere. You will get a min of 1000 MQMs for a round trip (500 each way). The remaining 916 MQMs will roll over into 2010 and you will only need 24,084 MQMs earned in 2010 to re-qualify for Silver in 2011.

Right now, if you don't hit 25K you will get NOTHING rolled over into 2010 - zip, nada, zilch, bupkis. You will start from scratch as if you had never earned that 24,916 in 2009. Don't count on Delta to say "you got close enough". With the new rollover MQMs it is likely they will not be budging on the thresholds for Medallion qualification. Also, some (including me) suspect there will no longer be "soft landings" due to rollover MQMs.

Fly dammit fly!