Dropbox, the file syncing and sharing service, has updated their iPhone app. Version 1.5.5 adds the ability to post links to Twitter and Facebook (either as a post or a message), as well as support for AirPrint, and support for the Korean language.
This is in addition to the ability to send links to files via email and text message, already included. The share feature does not send the file, folder, or image itself, but a link to the file on the Dropbox server. When the sender wishes to stop sharing the file, he can log into Dropbox and cancel the link.
The new version of Dropbox is available at the App Store, and requires a Dropbox account (first 2 GBs of storage are free).