How to implement a plugin featuring foursquare like check-in

Question

I need to add a check-in feature (very similar to foursquare check-in) in worpress based site.

There will be "Check in" button at the top of the web site, and clicking on it the visitor will be presented with a list of places.

1. Can somebody guide me to decide which one is more suitable for wordpress architecture?

   i. Clicking the "Check-in" button, make an AJAX call and present the list of places as a modal dialog. ii. Clicking the "Check-in" button, present a Worpress page with list of places and a submit button.

2. Where should I host the server side API? Use Wordpress XML RPC or as a separate API application(May be on a different server and cross site AJAX call can be made via php-curl proxy)?

Answer 1

I would use an AJAX call + modal dialog.

And for the API, just create a plugin, and follow the steps on this page to create your own custom ajax action.