You can get a bit of extra space in your DropBox via their free promo, via this lifehacker article. Only downside is you to get the final 128mb you whore out your FB and twitter account for them, and it's not 100% obvious from the page that's what you're doing (though after you connect your facebook and twitter account to dropbox, and then 'updating' on why you love dropbox it should be pretty obvious).

Of course, you can be a bit evil and connect the accounts and then revoke access before posting the 'update'. That said, I love dropbox and promote them when I can because it's an awesome free service (I just don't like companies spamming my social feeds).