There was
this thread about an alternative. To be honest, I've never seen a home-built one work as well as a PullPal, and Madizell can probably tell you about his experiences in the Outback Challenge. Not to say that home-built ones can't be effective as ground anchors. They just usually aren't
as effective as the PullPal- unless they copy the geometry and blade design fairly closely. PullPals aren't perfect and can be improved upon, but they are the best thing I've seen commercially available.
There are elements of the ARB design that I find well thought-out from casual examination, like how the point is a separate piece from the wings, giving a stronger digging point. I also like the handle for extraction and guiding it into the soil. I'm not sure about the length or angle of the arm- especially when a deeper set is needed. It's possible the angle can be adjusted, but I'd have to see the design up close to see if I liked it.