If you don't mind something very cheap, the Branwavz M1 can take some punishment. I've put them through the wash and dryer in my jeans pockets and they're still running fine now. The dryer melted the glue so the drivers came off the casing, but gluing them back together with superglue wasn't too hard. However, it has no strain relief going into the earbuds so I'm not sure how long that'll last. I've always babied my earphones though, so I don't know how well it'd respond to rough treatment.
Regarding the UM2s, I wouldn't quite trust how sturdy it is. I have the UM3X and the tip has come loose before. Not a fun thing to experience. The connection with the removable cable could also start cracking. The Westone 3/4 apparently have better build quality than the UMs, using a better quality plastic but might also be more than you're willing to spend.
WITH the drivers still glued to the housing.
