While it was originally rumored to be a .jp only release, InCase is now offering the 3G iPhone case from Fragment Design online. Limited to 1 a customer, this collaboration yielded four different slider case variations, 2 black and 2 white (one glossy, one matte). At $49.95, they are a $15 premium over the regular slider case, but the limited nature and collaboration with Fragment means these won’t last long.
I just bought the matte black version. You are limited to 1 per customer which is probably a good thing, considering resellers already have them on eBay for $120 each. Pick yours up here (and InCase has free ground shipping!).