I installed Easy Release from http://www.applicationgap.com awhile back while it was in it’s infancy. The latest update allows for custom logo’s, custom releases, etc. You can bring up a release, add the model’s photo, have her, you, and a witness sign it on the iPhone, and have it send you and the model a PDF version of the release. See the screencap below of a sample release.
Of course, they explain it better:
Easy Release by ApplicationGap replaces inconvenient paper release forms with a slick, streamlined application designed by professional photographers for professional photographers. Easy Release lets you collect all the data and signatures you need right on your iPhone, then mails a PDF and JPEG of the release right to you. Easy Release uses industry-standard and proven legal language that is accepted by the world’s leading stock photo companies, like Getty Images and ALAMY. Plus, Easy Release supports 12 different languages, so you can get the release you need, no matter who, or where you are shooting.