Today, Adobe unveils the public beta version of eSignatures, a cloud-based service that lets you easily add your John Hancock to documents online. Upload your document, insert the recipient's e-mail, select a date, insert a message and then sign. The finished document is certified to ensure that it hasn't been altered since the signature--- if it is modified in any way the certification tag disappears. The process is dead simple (it took me less than two minutes from start to finish) and best of all, it's free.
According to an Adobe source, eSignatures may eventually be integrated into the Acrobat.com service since they share many of the same underlying technologies (an integration with Acrobat.com may also open up monetization opportunities).