From a colleague's e-mail autoreply:
I am away for the summer semester and will return Aug 15, 2007. I will not be able to respond to your e-mail until then.
This is a pretty common occurrence in academia. Postsecondary faculty that aren't teaching during the summer will disappear for a few months and then resurface in the fall. Many leave answering machine messages and/or e-mail autoreplies that they're gone, completely unavailable (literally) to anyone who might want to reach them. They're recharging their batteries and taking advantage of the quiet time to work on articles, books, and other projects. It still strikes me as sort of odd, though, to simply disappear like this.
Other than K-12 teachers, I can't think of any other professions that simply vanish for months at a time. No postal mail + no telephone + no e-mail = no contact.
[photo credit: www.flickr.com/photos/ron_richardson/280329347]