Hey, kidney girls and kidney boys! Come on down to the Kidney Kids Health Fair! Laugh and sing and sign an organ donor card ($2 off the admission price!), all the while learning about the wild world of kidney disease! Why, there’ll be blood pressure screenings (“Pump you up!”), kidney X-ray viewing (“Creepy!!”), alarmingly vague “free giveaways” (“Look, Ma, a lung!”), and if the appetite survives, refreshments (“Liver paté—yumm!”). From 11 a.m.-4 p.m. today; noon-4 p.m. tomorrow at the Capital Children’s Museum, 800 3rd St. NE. $6. (202) 543-8600. (Dave Nuttycombe)