Okay guys I can provide significant insight for you. I started my virtual assistant business after working for a "turn key" office company for 6 months.
The "turn key" office is one large office (in my case about 12,000 sq feet), that is broken down into mini offices for small business owners to lease at an affordable rate. They share a community break room, copier, fax, scanner, shredder, receptionist, lobby, etc.
They also offer "virtual offices" whereby our clients get a prestigious business address, a virtual phone number, which is a land line phone that you have either forwarded to a voice mailbox that you pick up via email or phone when you are available, OR can have forwarded to your cell (which is my preference). Mine is actually answered by a receptionist and forwarded to me (announcing the caller) on my cell.
This way you can work in multiple cities and have a presence wherever you need one (virtually). The monthly packages are not very expensive either. When I worked as their employee, some virtual clients actually just had me scan their mail and email it to them.
It's a great arrangement.
Food for thought.

Sandy