Recently, I set up a wireless hotspot from my house that will let me have free internet access in a lot of the places I travel. That's because the company that makes the wireless mini-router I'm using has created a global community of hotspot-providers who give wireless access to everyone in the community who is within range.
All of this is the work of a European company called FON, which was launched last year with millions of dollars in funding from Google and Skype, among others. Their routers piggyback on the existing broadband service of their members, and cost a one-time fee of around $30 to users who pledge to allow others in the community to access their wireless. (Users who are not in the community are charged $3 for daily access to a hotspot.)
The 54 Mbps speed on the FON router isn't quite as fast as my current wifi service, but it works great, and is certainly better than most of the wifi coverage that I've sniffed out while traveling. And while you're unlikely to find a hotspot everywhere in the world, a quick look at the FON map shows that most major cities are adequately covered. As the community grows, so will the coverage area.
Before you rush out to buy a FON router, though, keep in mind that some ISPs (including Comcast) aren't all that tickled by the prospect of their users helping another for-profit company. (Gizmodo has a debate on this very problem—and a hardware hack for those looking to protect themselves.)