DocUSign
Provides the services needed to sign and move legal documents around as needed.

Drop Box
Quickly and easily move files from your computer to another by simply sharing folders.

Send This File
This service requires a free registration to use. According to Blind users it is quite easy to use. How Easy Is It? Enter the recipient's email address. Select the file. Click the SendThisFile button! The recipient receives a link to their file via email. No email attachments. No software to install. • No file size limit! • No limit on files sent! • Security same as email!

Sign.com
Send a signature request, offers a variety of plans.