if you are overseas the best that i have found is this website LINK it isn't free $5 bucks per month (there is a free 7 day trial you can try without having to enter any information so you can test it). Basically it uses a DNS change to tell websites your location. It works great with ESPN3 but also Hulu, Pandora, Abc.com, netflix and most other US sites that are US only.
The way I did it when I lived out of country was get a hold of a proxy. A private one is best.
for firefox , go to tools > options > Advanced > network tab >settings > click the manual proxy button, enter your private proxy... click ok. Bam.
No downloads, no paying money.... just easy proxy viewing on any internet game carrier.
You can google for lists of proxies...