For many links between pages on the same folder level, I use relative paths (like home/products/contact, etc.).
Once you move to a deeper level, of course, those links need to be adjusted. One way of dealing with this would be to change all the links to absolute paths (http://www...). Then I could just reuse the same code on all folder levels.
I'm just curious to know if there is any speed penalty of using one way over the other.