Droplings is currently free during its beta stages of development. It requires a Dropbox Pro Account
is a menubar icon. If you drop a file on it, it'll build a nice preview page around it, upload both to your Dropbox, then copy the public preview link to your clipboard. If you drop a folder on it, the folder will be zipped up before uploading.
Droplings comes with a clean preview page theme -- see the download link below for an example -- but you can use your own custom themes. (There's documentation on how to do it.)
The maximum size of the files you share is only restricted by the size of your Dropbox account. If your account has 1.5GB free space left, then that's your upper file size limit.
Droplings requires OS X 10.6 or higher, running on 64 bit (i.e., any Mac built since 2007 should do). You'll need a free or Pro Dropbox account, too.
I wrote it because I'm a freelancer and often need to send files to clients. I feel having a branded preview page makes for a more professional appearance.
Droplings is free at the moment as the 0.9.x versions are considered beta. So, there might be bugs. Once we reach 1.0 there'll be a (modest) price tag.