goodroi - 1:48 pm on Mar 22, 2013 (gmt 0)
Welcome to WebmasterWorld!
It depends on your personal situation. Adding a site-wide link may make sense for a 100 page website, but a 100,000 page site has different issues and it might not make sense.
I prefer to spend less time obsessing over how to conserve pagerank and link juice from within my site and instead focus more energy on gaining inbound links and additional sources of pagerank to all of my key pages (homepage & deep ones).
The best way I find to getting indexed is having great backlinks. Great backlinks tend to easily overcome deficiencies in most other areas.