I notice a lot of trends in StackOverflow--lately I've noticed a pretty massive swing to android--it has more questions than Java and iPhone combined right now.
This doesn't exactly mean any one thing--It could mean that the iPhone is much easier to program or it could mean that Android is more popular right now or that Android is easier allowing more people to try--but regardless the info would still be really interesting to see.
I'd love to see how many questions are tagged C++ vs C# vs Java, what percentage of C questions involve pointers, what other tags are most common on Java questions, etc.
This info would be useful both as instantaneous counts and graphs over time.
Has anyone made such a tool--or is there one hidden her somewhere? If not I'd like to suggest one be considered.