I would like to introduce new module Search API Location that provides possibility to do spatial search using Apachesolr.
At the moment we can search by radius on the map putting the center of the circle. You are welcome to test on Demo site.
Technical details

Search API Solr module is used for integration with Solr. Search API Location module exports location data to Search API via hook_entity_property_info_alter().
Apachesolr itself uses LocalSolr library that should be compiled into apachesolr. You can follow instructions in README to compile apachesolr or download ready apachesolr from demo site.
Demo site Location Search is built as a view. Search API Location module provides exposed filter for radius with slider.
Hope you enjoy and welcome to participate in development of spatial search functionality for drupal.Tags: drupal planetapachesolrsearch api