Been using this for a while now and thought I'd share. Works with both my XA10 and XF100:

Mizomi Photography: DIY Spider Holster alternative for the Canon XA-10 camcorder (http://mizomi.blogspot.com/2014/03/diy-spider-holster-alternative-for.html)

Thanks Todd! I picked up one of these when I was in the states and used it extensively in the field for a week. It works great, and cheap at twice the price!