Implementing In App purchases in Android?

Edit: Android now supports in-app billing! Original question: It looks like Android won't natively support in-app purchases for a while, and when it does there might be a huge user base with devices that don't support them. What's the best way to implement iPhone-like (additional content or services) in-app purchases in Android using the Android Market if possible? The solution should consider in particular: - For all kinds of in-app purchases: Android Market's 24-hour cancellation policy - For consumables/non-consumables: storage of additional content (ie: use precious application memory to avoid piracy, or use SD card to avoid bloating application memory) Thanks!