First of all I want to thank you all at the Census for your brilliant effort in providing a usable API. I think the documentation needs to be improved, though, with more examples of string requests and possible use of wild cards, if any.
I am currently working on a web application where I want the user to visualize demographic indicators within a certain distance from a specific/user-picked LatLong (for instance total population count within 5 miles, or % of Hispanic people for each block group within a tract), but I can't find any information on how to retrieve, through the API, the census' geographic boundaries (tract, block group or block) in order to plot them on a map (Google), or how to get a list of all block groups within a tract or blocks within a block group.
Is this at all possible? If so, can you please give me some direction?