Funny you brought this up.  I just got my new "digiscoping" set up in the mail today.  It's a Celestron telescope with 100 times optical zoom that I can attach my DSLR to.  Obviously the digiscoping pictures are still just that - digiscoping, but you can sure get some good pictures at a distance.  The barn below is over a mile away from my house.  Plus I can add my Tamron 1.4x converter onto it as well and get 140x zoom! 
I circled the barn in the perspective picture.  The digiscoped picture is with the 100x zoom.