As of Tue Oct 21 19:44:49 2008 (Eastern time zone), the following recent tweets could not be favorited via API. Spot checks on a few indicate web interface similarly non-functional. Other users such as @abigvictory and @texburgher reporting similar failure-to-favorite behavior.
http://twitter.com/girlmonkey/statuses/969575107
http://twitter.com/Sontra/statuses/969608782
http://twitter.com/jdickerson/statuses/969611877
http://twitter.com/srah/statuses/969612478
http://twitter.com/jefferyharrell/statuses/969614959
http://twitter.com/FakeSarahPalin/statuses/969618290
http://twitter.com/peeppeep/statuses/969621777
http://twitter.com/bcompton/statuses/969627809
http://twitter.com/kristastevens/statuses/969628957
http://twitter.com/leftbrainstupid/statuses/969633580
http://twitter.com/lindstifa/statuses/969640491
http://twitter.com/lindstifa/statuses/969641407
http://twitter.com/abigvictory/statuses/969647471
http://twitter.com/Jessabelle207/statuses/969649190
http://twitter.com/brianmadden/statuses/969649211
http://twitter.com/hotdogsladies/statuses/969656741
http://twitter.com/FanEffingTastic/statuses/969656909
http://twitter.com/Remiel/statuses/969657093
http://twitter.com/echuckles/statuses/969657336
http://twitter.com/toldorknown/statuses/969657735
http://twitter.com/FanEffingTastic/statuses/969659703
http://twitter.com/bsheepies/statuses/969661485
http://twitter.com/SeoulBrother/statuses/969668271
http://twitter.com/printartist/statuses/969671138
http://twitter.com/califmom/statuses/969685513
http://twitter.com/califmom/statuses/969692486
http://twitter.com/michael_egan/statuses/969693111
http://twitter.com/MissRFTC/statuses/969693198
http://twitter.com/califmom/statuses/969696163
http://twitter.com/cracked/statuses/969711994
http://twitter.com/mayjah/statuses/969718359
http://twitter.com/smartgoat/statuses/969720985
http://twitter.com/badbanana/statuses/969722396
