For sharing, I now almost exclusively use Evernote. Since they removed the filetype restrictions for free users, you can attach any filetype to a note and share the note. It is as simple as dragging and dropping the file into the note.
The only thing to watch is the upload limit, since you are allowed 60mb (free) per 30 days.
So if you wanted to upload more than that amount, a service like that would be better.
Also, Box.net has a good free deal at the moment. If you sign up via an ipod/phone then you would get 50gb of storage.
Though, there is no free desktop app, so uploading from a desktop could be awkward.
(also, you would need an ipod/phone
)