How can you watch ESPN3 outside the US?

ESPN has deals with leading ISP around the world to carry E3 content.  For example: SingTel Astro Sky Foxtel Austar Panama: Cable & Wireless Chile: VTR Argentina: Fibertel Venezuela: Inter Milicom (Tigo) Milicom (Amnet) If you are in the EMEA region check your ISP provider and their portal page, most will have a prominent link to the E3 international player.

As the previous answers have noted, you can either find an ISP that has existing deal with ESPN to carry ESPN3 or you can do go around the system and do it yourself through a legal gray area. Basically, what you would need is someone (Preferably yourself) with a computer or server in the USA running on an ISP with ESPN3 access. You can then use that computer or server as a proxy for your Internet access. Your computer can now access ESPN3 as if it were in the USA using that ISP. This is a gray area because it's similar to how Slingbox works. Provided you're using your own computer and paying for the ISP connection, then technically you're only using your hardware and service to extend the connection to where you are at the moment.

One of the problem in Latin AMerica is that DirecTV has exclusive rights to transmit spanish league soccer games, so the content ESPN shows does not include this games.