Hi... And sorry for my bad english, I'm from Spain.
There's a free storage service called Megaupload (http://www.megaupload.com/), that allows files of 0-500 Mb. And later them can be accesed with a link, and by someone...
Maybe this could be an interesting alternative for the Yahoo briefcases.
Megaupload 100MB acc max for free per slot, more than 100MB and you have to pay. Plus they forbided multithread download resently and the speed is too slow and downloads become corrupted frequently. Come2store would be perfect if someone finds out how to bypass that nasty referrer check.
I think that yahoo briefcase and come2store are ok. They are secure, although it would be nice if exists a site that let's you upload whatever you want, give you good bandwidth, have no time restrictions...and...never (NEVER!!!) delete your files.
Well, it's just a little dream but who knows!, If only Google start a service of uploads and downloads....like you said only in my dreams but the future has surprises.