Okay, so I found this mod on the weekend, and it is like the best mod I have ever used.
Link (Current 1.3.2 version)
You can now slide and rotate blocks (and fire them from a cannon!)
I encourage everyone to check it out.
And if anyone plays around with it, and gets it to work, I would LOVE some information on the Slide Slant block.. I can't find anything anywhere on how to use it, and I translated the original Chinese page and it wasn't very useful.. it's the only block I don't know how to use.