Ear-canal phones w/ in-line volume control: do they exist?

I am searching for good in-ear-canal headphones with in-line volume control. Sony has on-ear earbuds, but I'd really like canal-phones like Sennheiser or Etymotic (app. $50-$75). Any recommendations? Why do so few headphone models -- and none in the mid- or high- price ranges -- offer in-line volume control? SO much easier when listening to an Ipod.

hmm, not any that I know of, but I think some companies make inline adaptors specifically for headphone...

such as something like this

hope this helps!

Thank you, that is very helpful. I didn't know those were made.
Do you think they affect sound quality?

lol, they probably don't affect sound quality much. Koss is decent.

let me put it this way: it won't make any noticeable difference unless you're listening on top-of-the-line 'phones.