Dropbox Share Online Storage [invite]

Interesting, let's see

Spread the word about Dropbox and get extra space!

Earn up to 3 GB of extra space free (6 GB if you're a subscriber), just by inviting your friends to join Dropbox!

I was already signed up before this invite bull. Do I get this extra space?

Shouldn't really suggest this, but if you just invite using that gmail trick. You get 250mb extra storage for each invite. Easy way to get more space

Which are the best online storage sites?

Stuff like photos,PDF's,word documents,music etc...

Without being shared...