Simple. Go to Starbucks. By registering any gift card on starbucks.com (they go low as $5), PSP owners can get free internet access on their PSP systems. The catch? It's only limited to two hours a day, and you have to use your card in some way (buy something, or add value to it) at least once every 30 days. For portable internet browsing on the go, these restrictions are pretty generous.
Once connected, PSP is able to browse the internet at quite a respectable speed. There is one glaring flaw, though. You won't be able to use the free wi-fi for anything but internet browsing. Unfortunately, it doesn't appear online gaming will work at a Starbucks wi-fi spot.