buy linden dollars (currency of second life) with a credit card. Then use virwox to exchange those for bitcoin. That's really the only method I've seen out there
unique idea! I hadn't heard about that method. Maybe it's time I resurrect my avatar which I haven't touched in 5 years...
Be forewarned, there's a limit to how much you can charge (I think it's about 60 USD at a time), on top of a hefty fee for using your card, and sometimes it doesn't work (as is my case; my bank didn't like it for some reason, so it wouldn't work.)
Otherwise, there's no other way. You can thank the chargeback for this; and also, that's why PayPal is discouraged, as well.