Anachronisms: Sorting out technology in fiction

As I close in on publication of my first novel, I sent it to a trusted friend for a final proofreading. She found a few things but even more importantly, she brought up the issue of technology and a time-setting for the book.  I wrote this book in 2008-2009 about three people in their late 30s/early 40s. It was set in 2006 and includes the technology I myself was using then, not necessarily the technology others might be using.

In the book, I have the following:

• Characters using email
• Characters using answering machines
• Characters using cell phones and land lines
• Characters passing along information on a slip of paper (a phone number) [instead of telling someone to look it up on the web]
• Characters looking up information on the web
• Characters leaving each other notes on a door or a car
• Characters writing love letters to each other through snail mail
• No characters are texting
• An artist sending images on a CD to a gallery
• Same artist has a web site
• Main character has a CD collection

Jan argued that I need to rethink all of these things or set the time back 8-10 years. It poses an interesting dilemma. Which of these are anachronisms? Which of these are characters' idiosyncracies? (I know both young and older people who collect vinyl records). So I will go in and look at all these places.

Something to consider as we write.