Here's a clip of me going from soft to hard without using my hands:
XTube Videos
If the link doesn't work, just go to XTube, find user Slender77, and look for the "Hands-free Erection" video.Be patient. I wanted it to be real, so I made sure I started totally limp. It just barely starts to grow between 40 and 50 seconds into the video, and it doesn't really start taking off until about 1:10 or so, but it does reach full erection by the end of the clip and then you can pause it and toggle back and forth between two different points to make a good comparison.Hope you enjoy it!