Jogging Phones for the Apple iPod Nano

Hi there, has anyone tried the Etymotic ER-4S with the Apple iPod Nano?
I had a pair and liked em before getting the Nano, but had them stolen at a gig.
After those, I tried some cheap Skull Candy inkD, which broke, but were ok, for the price (ok for skaters), but broke.
Temporarily, I have a pair of Panasonic Ergo Fit earbuds, which were very cheap and recomended at the store, but sound broke (poor highs and mids, but ok bass delivery).

I know the Etymotics were ok (not as nice as Sennheiser HD580's say imo, but a different beast), and could sound like music, but am unsure of the other in-ear phones on the market.
Ideally, I'd like something small, rugged, and that won't fall out when jogging on a treadmill, since that will be the main (and almost only) use, since I prefer Stax for regular listening at home.

How about other phones, as good as the Etymotic, say with less isolation? I don't mind the sound of the treadmill, and it's better to hear some noise around me, if others are talking, and I should be listening to be polite. :)

Thanks.