Using velostat and a non-woven conductive fabric you can craft a simple pressure sensor for wearable computing and eTextile projects.
Use the velostat as a semi-permiable layer between two pieces of conductive fabric to create an interactive switch.
Insert this basic pressure switch along either the negative or the positive trace then push it to complete the circuit.
How-To DIY video tutorial can be found on The eTextile Lounge 8 November 2011 blog post.