I'm a stickler for grammar and punctuation. On the "Contact" page, there should be a colon after "I can be reached by the following means" instead of a period. Also, you spelled "fell the need" instead of "feel the need."
Additionally, if you look at the "Gallery" page, then you'll see that "Robert S. Irwin Photography" in bold letters is not centered and is not the same sized font as the "About," "Contact," and "Guestbook" pages.
Lastly (although this may be only a matter of taste), my screen resolution is set to 1028x768 and I have to scroll down just a tad in order to view the entire home page. I would prefer it fitting neatly onto my browser when it is maximized so that I don't have to scroll down.
Otherwise, the website looks very clean and professional. It's easily navigable and intuitive. I like it very much. Sorry for the criticism, but I was a web site designer in a past life.