If you travel a lot and want a nice place to work no matter where you go, then you should check out Regus. I don’t get any money for recommending them, I just like them and use them frequently.
Regus has offices in most major cities all over the world, and they do their best to be located in the nicest and/or most central buildings in any given area. For an annual fee you can use their “business lounges,” where you can work in a either a cubicle or an open area, and use all of their office admin services (faxing, internet, postal mail, etc).
For extra cost you can also rent an office or conference room by the day or the hour. This is a lot more expensive though, and in most cases the business lounges are all you’re going to need. One trick is to purchase prepaid Regus office space cards at a local big box office supply store like Office Max or Office Depot. The office space is much cheaper that way. The problem is these prepaid cards aren’t sold everywhere, so call the store before you go.
I have a lifetime membership to Regus, use them extensively, and I’ve never been dissatisfied. If you travel often, or even just want an office space away from home, I highly recommend them.