Sony is finally allowing PlayStation Network users in North America stock their PSN wallets through PayPal. The feature was already available in Europe, so we're a little behind on this one.
One thing to keep in mind is that this can only be done online by signing into your Sony account. There is currently no option to use this feature directly through your PlayStation 3 console. Slight bummer, that.
Anyway, funds can be added via PayPal in increments of $5, $10, $20, or $50. The whole process is pretty simple: just hit "Add Funds to Wallet" twice, select "PayPal," and pick your "Funding Amount" from the dropdown. The rest should be familiar to anyone who has ever used PayPal, where you'll be directed to the PayPal website to confirm, and so on.