Wordpress question regarding Tweet This w/ custom URL shortening

[PornMD]

Figured someone here might know the best way to do this...IMO I may not need the Tweet This for it but would still like to use their Tweet This button.

Let's say the URL of post is "longdomain.com/1/long-post-title" where "1" is the post #.

I would like to use a short url "sho.rt/1" with the 1 matching the post # URL. As it is, I've noticed that longdomain.com/1 goes to the post too but doesn't actually redirect to the longer URL, which in and of itself concerns me because I don't want dupe penalties, but am not sure which plugin is the best to prevent that from happening.

That said, I do WANT longdomain.com/1 to work and redirect to the long URL, because if that happens, I can simply set up sho.rt to redirect everything to the same URL at longdomain.com (sho.rt was only gotten for this purpose basically).

It doesn't seem like there's an easy way to set Tweet This though to work specifically with sho.rt/%post#%. The whole point of it is to work with URL shorteners that use random letters/digits for the URL which is not what I want. Is there a way to modify it to do what I want or is there an easier way to deal with it but still use their image?

[PornMD]

Anyone??