A search in the Market for "Stackoverflow" brings up a couple of widgets and question browsing apps, including at least one (Droidstack) where you can add Android-Enthusiasts and browse and search questions, etc, but it's buried fairly deep in the app.
Given the Android Market provides direct access to the exact audience we are looking for, surely a dedicated app would be a good idea? Marketed in the right way (i.e. as a Q&A app for the phone in your hand, rather than talking about stack exchange generally) it could be quite popular and presumably generate a fair amount of traffic.
This seems a bit obvious, so apologies if it has already been explored and I've missed it. If not, then what could we do to make it happen?