I just moved.
I used to fly United as it gave me the most options.
Now I am closer to another airport, and Delta gives me the most options - with very very few United options

I am aware that I can get a status match, but is there a way to transfer my miles from United to Delta?
Years ago I remember that there was a site that allowed such things, but I don't remember its name.
Would I be able to transfer the miles via another program? e.g. United to Starwoods to Delta?
Is such a move doable? If so, is it even worth it?