Pitching your tarp diagonally reduces the number of guylines you need from 4 to 2 - in this arrangement I have often been able to tie these two corner guylines to other nearby trees, rather than having to put pegs into the ground to tie to. This can significantly reduce the length of your guylines to only a foot or two, which is short enough that you can just remember the tree its tied to and avoid that, instead of the huge length of line that you might ordinarily run away from the tarp.
Of course this relies on a suitable number of trees in your area
Personally, I sleep too cold to generally use a hammock except in the midst of summer (although they are very comfy) - and I generally use a tarp pitched as follows:
http://www.see.ed.ac.uk/~mrichar1/images//2005-07 BushcraftUK Scottish Meet/Match/8.jpg
(Note I also use a bivvy bag in this setup, or a second ground-sheet).
Of course this relies on a suitable number of trees in your area
Personally, I sleep too cold to generally use a hammock except in the midst of summer (although they are very comfy) - and I generally use a tarp pitched as follows:
http://www.see.ed.ac.uk/~mrichar1/images//2005-07 BushcraftUK Scottish Meet/Match/8.jpg
(Note I also use a bivvy bag in this setup, or a second ground-sheet).