I completely agree with this article - if you're doing a PhD just to get a bigger salary at the end of it then you're probably doing it for the wrong reasons!
I think the value of a PhD is "personal growth" and improvement (no matter how slushy that sounds). For me that's been the most noticeable thing and by far the best. Bex, I agree - I doubt the financial rewards (if any) would keep me going!
I found some of these points quite challenging, but also made me think about what I am actually doing and what I need to do. There is another article somewhere "A PhD is not a nobel prize" also worth reading to remind of scope of graduate research.
Thanks for this Bex, it's always good to get references to this sort of material. I have had a research blog since Nov 2008 and see it as a way to strengthen 'the researcher as research instrument' that is me. I wrote a guest post on thethesiswhisper.wordpress.com blog a couple of months ago on social media and the phd and there are a few more references in that. See http://thethesiswhisperer.wordpress.com/2010/08/31/social-media-and-your-phd