TransferBigFiles is the desktop app for the TransferBigFiles.com service. It allows you to send files to anyone with an e-mail address. There are different plans available, including a free one. The free plan, the one I tested, allows you to send up to 1 gigabyte worth of files no bigger than 100 megabytes. Each file can be downloaded up to 20 times, and there doesn't seem to be an upload or download speed limit.
When you first start the application, it will ask you for your account details. If you don't have one, the "Sign Up" button will take you to the website and you can get one there. Initiating a new transfer is such an easy process. All you have to do is select the files that you want to send, and write the e-mail address of the people you want to send it to. There are a few advanced options here. You can password-protect the download, select the server you want to upload your files to and choose to receive a notification when your file has been downloaded. Of course, you can add a message to this e-mail. The users that download your file don't need to have TransferBigFiles installed on your computers.
TransferBigFiles works very well. It was fast enough and the file that I uploaded with it could be downloaded with no problems. The paid accounts are very interesting and not that expensive. This app is worth a look if you send lots of files from your Mac.