> Finally, I was thinking a -f flag to cat (cat -f <=> tail -f) would be
> useful.  comments?  

I routinely use "tail +0f". In new syntax, that would be "tail -f -n +0". 
People who can remember that tail starts counting at 1 rather than at 0
might prefer "tail +1f" or "tail -f -n +1". 

I don't see any need to add another option to cat for this.

--apb (Alan Barrett)