Billing themselves as "dead simple file sharing for design and media professionals," BoxCloud seems to have a good thing going here. If you deal with a lot of clients and customers who simply aren't hip to FTP or other ways of transferring large files, BoxCloud offers a pretty simple, nay - dead simple - alternative. Featuring software clients for both Windows and Mac OS X (though when Download Squad found them last year they apparently offered a Linux client too), all you need is someone's email address to share a file of any size with them. Your lucky recipient, be they a client, friend, family member or co-worker, will receive an email with a link to download the file from your BoxCloud page. But herein lies the twist: BoxCloud doesn't host the file, so you aren't charged for space - your computer must be running BoxCloud's client, be on, and connected to the internet in order to share the file (i.e. - you host it). Their service plan then simply charges you for monthly bandwidth, not storage space, and plans start at 1GB/month for free, moving on up to 20GB for $9/month.
Sure, anyone who's domain + hosting savvy will scoff at this service, but anyone looking for brainless and painless file sharing might appreciate BoxCloud's simplicity. If you're interested, take their tour for more info on how simple sharing can be.