Google charts

I've added some Google charts to the front page of the TreeTapper site. I'm using googlechartseasyphpclass v 1.02 to more easily generate the code to call the charts (it involves converting numbers to letters for plotting, for one thing), though it does limit flexibility a bit (but the source code for the PHP script can be modified easily). YUI also has a new charts API, but it requires a very recent version of Flash for people to use (more recent than I had in FireFox) -- Google can simply create a png, which is convenient. The code to make the data to pass to the charts takes a little while to work (dozens of postgres calls): I might just update this daily and have the site call a saved version of the data. The charts I've made allow tracking of how much the database has grown in the previous month as well as breakdowns of references by year.