I've used MiniDisc portable players, not an iPod, and although I like
Grados in general, carrying around headphones that are bigger than the
player seems silly, IMHO. I only use my Grados at home.

I'd go with earbuds from Shure or other brands. A cheaper choice would
be the Sennheiser MX series. I bought my MX 300's off eBay for
practically nothing, and for music on the go, they sound and work fine.
If I want bigger and better sound, I have Grados at home.

If you really want headphones, I suggest you look at folding
headphones, like the Sennheiser PX series.

If you decide to go with Grado, look for the SR40. It's smaller than
the SR60, but uses the same hardware. I think the SR40 is discontinued.
I bought mine off eBay a few years ago, so that's probably the best
place to shop.

BTW, if you search the web and newsgroups via Google.com, you'll find
about a zillion opinions that might be useful to you. There are web
sites that specialize in ear gear also.