I am just a couple of baby steps from being able to take my entire office with me (well, not the furniture) wherever I go. My files are all digitized and stored (encrypted) on my laptop (and backed up daily), I send and receive faxes electronically, and I use Skype so that I can pick up my phone from anywhere I have a wireless connection. Most attorneys are willing to receive e-mail rather than paper mail, and since at least half of my work is in federal court, electronic filing means I do not need to generate paper. (Come on, Minnesota state courts!)
The only thing I need is a way to get my paper mail electronically so that I only have to stop in once in a while to pick up original copies. If I someday hire a secretary or paralegal, then they can do it for me, but until that day, I still have to stop in the office every day or so to check my paper mail.
(I could also use a portable scanner, but there are plenty of options; I just don’t want to carry one around.)